diff --git a/openslides/agenda/access_permissions.py b/openslides/agenda/access_permissions.py
index 9d1738f44..940e5a3b0 100644
--- a/openslides/agenda/access_permissions.py
+++ b/openslides/agenda/access_permissions.py
@@ -1,7 +1,7 @@
 from typing import Any, Dict, Iterable, List, Optional
 
 from ..utils.access_permissions import BaseAccessPermissions
-from ..utils.auth import has_perm
+from ..utils.auth import async_has_perm
 from ..utils.collection import CollectionElement
 
 
@@ -9,11 +9,7 @@ class ItemAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Item and ItemViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'agenda.can_see')
+    base_permission = 'agenda.can_see'
 
     def get_serializer_class(self, user=None):
         """
@@ -26,7 +22,7 @@ class ItemAccessPermissions(BaseAccessPermissions):
     # TODO: In the following method we use full_data['is_hidden'] and
     # full_data['is_internal'] but this can be out of date.
 
-    def get_restricted_data(
+    async def get_restricted_data(
             self,
             full_data: List[Dict[str, Any]],
             user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
@@ -47,11 +43,11 @@ class ItemAccessPermissions(BaseAccessPermissions):
             return {key: full_data[key] for key in whitelist}
 
         # Parse data.
-        if full_data and has_perm(user, 'agenda.can_see'):
-            if has_perm(user, 'agenda.can_manage') and has_perm(user, 'agenda.can_see_internal_items'):
+        if full_data and await async_has_perm(user, 'agenda.can_see'):
+            if await async_has_perm(user, 'agenda.can_manage') and await async_has_perm(user, 'agenda.can_see_internal_items'):
                 # Managers with special permission can see everything.
                 data = full_data
-            elif has_perm(user, 'agenda.can_see_internal_items'):
+            elif await async_has_perm(user, 'agenda.can_see_internal_items'):
                 # Non managers with special permission can see everything but
                 # comments and hidden items.
                 data = [full for full in full_data if not full['is_hidden']]  # filter hidden items
@@ -72,7 +68,7 @@ class ItemAccessPermissions(BaseAccessPermissions):
 
                 # In non internal case managers see everything and non managers see
                 # everything but comments.
-                if has_perm(user, 'agenda.can_manage'):
+                if await async_has_perm(user, 'agenda.can_manage'):
                     blocked_keys_non_internal_hidden_case: Iterable[str] = []
                     can_see_hidden = True
                 else:
diff --git a/openslides/agenda/apps.py b/openslides/agenda/apps.py
index ed5434341..3629d1407 100644
--- a/openslides/agenda/apps.py
+++ b/openslides/agenda/apps.py
@@ -1,3 +1,5 @@
+from typing import Any, Dict, Set
+
 from django.apps import AppConfig
 
 from ..utils.projector import register_projector_elements
@@ -12,15 +14,15 @@ class AgendaAppConfig(AppConfig):
     def ready(self):
         # Import all required stuff.
         from django.db.models.signals import pre_delete, post_save
-        from ..core.signals import permission_change, user_data_required
+        from ..core.signals import permission_change
         from ..utils.rest_api import router
         from .projector import get_projector_elements
         from .signals import (
             get_permission_change_data,
             listen_to_related_object_post_delete,
-            listen_to_related_object_post_save,
-            required_users)
+            listen_to_related_object_post_save)
         from .views import ItemViewSet
+        from ..utils.access_permissions import required_user
 
         # Define projector elements.
         register_projector_elements(get_projector_elements())
@@ -35,13 +37,13 @@ class AgendaAppConfig(AppConfig):
         permission_change.connect(
             get_permission_change_data,
             dispatch_uid='agenda_get_permission_change_data')
-        user_data_required.connect(
-            required_users,
-            dispatch_uid='agenda_required_users')
 
         # Register viewsets.
         router.register(self.get_model('Item').get_collection_string(), ItemViewSet)
 
+        # register required_users
+        required_user.add_collection_string(self.get_model('Item').get_collection_string(), required_users)
+
     def get_config_variables(self):
         from .config_variables import get_config_variables
         return get_config_variables()
@@ -52,3 +54,10 @@ class AgendaAppConfig(AppConfig):
         connection.
         """
         yield self.get_model('Item')
+
+
+def required_users(element: Dict[str, Any]) -> Set[int]:
+    """
+    Returns all user ids that are displayed as speaker in the given element.
+    """
+    return set(speaker['user_id'] for speaker in element['speakers'])
diff --git a/openslides/agenda/models.py b/openslides/agenda/models.py
index 45ecae422..afca04c4a 100644
--- a/openslides/agenda/models.py
+++ b/openslides/agenda/models.py
@@ -182,6 +182,7 @@ class Item(RESTModelMixin, models.Model):
     """
     access_permissions = ItemAccessPermissions()
     objects = ItemManager()
+    can_see_permission = 'agenda.can_see'
 
     AGENDA_ITEM = 1
     INTERNAL_ITEM = 2
diff --git a/openslides/agenda/signals.py b/openslides/agenda/signals.py
index 36208d139..9411da5d0 100644
--- a/openslides/agenda/signals.py
+++ b/openslides/agenda/signals.py
@@ -1,11 +1,7 @@
-from typing import Set
-
 from django.apps import apps
 from django.contrib.contenttypes.models import ContentType
 
-from ..utils.auth import has_perm
 from ..utils.autoupdate import inform_changed_data
-from ..utils.collection import Collection
 from .models import Item
 
 
@@ -64,17 +60,3 @@ def get_permission_change_data(sender, permissions, **kwargs):
                 and permission.codename in ('can_see', 'can_see_internal_items')):
             yield from agenda_app.get_startup_elements()
             break
-
-
-def required_users(sender, request_user, **kwargs):
-    """
-    Returns all user ids that are displayed as speakers in any agenda item
-    if request_user can see the agenda. This function may return an empty
-    set.
-    """
-    speakers: Set[int] = set()
-    if has_perm(request_user, 'agenda.can_see'):
-        for item_collection_element in Collection(Item.get_collection_string()).element_generator():
-            full_data = item_collection_element.get_full_data()
-            speakers.update(speaker['user_id'] for speaker in full_data['speakers'])
-    return speakers
diff --git a/openslides/agenda/views.py b/openslides/agenda/views.py
index 48898237d..e0e295fd5 100644
--- a/openslides/agenda/views.py
+++ b/openslides/agenda/views.py
@@ -50,7 +50,7 @@ class ItemViewSet(ListModelMixin, RetrieveModelMixin, UpdateModelMixin, GenericV
         elif self.action in ('speak', 'sort_speakers'):
             result = (has_perm(self.request.user, 'agenda.can_see') and
                       has_perm(self.request.user, 'agenda.can_manage_list_of_speakers'))
-        elif self.action in ('numbering'):
+        elif self.action in ('numbering', ):
             result = (has_perm(self.request.user, 'agenda.can_see') and
                       has_perm(self.request.user, 'agenda.can_manage'))
         else:
diff --git a/openslides/assignments/access_permissions.py b/openslides/assignments/access_permissions.py
index f0dd3fe4d..e8d70e778 100644
--- a/openslides/assignments/access_permissions.py
+++ b/openslides/assignments/access_permissions.py
@@ -1,7 +1,7 @@
 from typing import Any, Dict, List, Optional
 
 from ..utils.access_permissions import BaseAccessPermissions
-from ..utils.auth import has_perm
+from ..utils.auth import async_has_perm, has_perm
 from ..utils.collection import CollectionElement
 
 
@@ -9,11 +9,7 @@ class AssignmentAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Assignment and AssignmentViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'assignments.can_see')
+    base_permission = 'assignments.can_see'
 
     def get_serializer_class(self, user=None):
         """
@@ -27,7 +23,7 @@ class AssignmentAccessPermissions(BaseAccessPermissions):
             serializer_class = AssignmentShortSerializer
         return serializer_class
 
-    def get_restricted_data(
+    async def get_restricted_data(
             self,
             full_data: List[Dict[str, Any]],
             user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
@@ -37,9 +33,9 @@ class AssignmentAccessPermissions(BaseAccessPermissions):
         only get a result like the AssignmentShortSerializer would give them.
         """
         # Parse data.
-        if has_perm(user, 'assignments.can_see') and has_perm(user, 'assignments.can_manage'):
+        if await async_has_perm(user, 'assignments.can_see') and await async_has_perm(user, 'assignments.can_manage'):
             data = full_data
-        elif has_perm(user, 'assignments.can_see'):
+        elif await async_has_perm(user, 'assignments.can_see'):
             # Exclude unpublished poll votes.
             data = []
             for full in full_data:
diff --git a/openslides/assignments/apps.py b/openslides/assignments/apps.py
index 301aaca79..555faf16c 100644
--- a/openslides/assignments/apps.py
+++ b/openslides/assignments/apps.py
@@ -1,4 +1,4 @@
-from typing import List
+from typing import Any, Dict, List, Set
 
 from django.apps import AppConfig
 from mypy_extensions import TypedDict
@@ -14,11 +14,12 @@ class AssignmentsAppConfig(AppConfig):
 
     def ready(self):
         # Import all required stuff.
-        from ..core.signals import permission_change, user_data_required
+        from ..core.signals import permission_change
         from ..utils.rest_api import router
         from .projector import get_projector_elements
-        from .signals import get_permission_change_data, required_users
+        from .signals import get_permission_change_data
         from .views import AssignmentViewSet, AssignmentPollViewSet
+        from ..utils.access_permissions import required_user
 
         # Define projector elements.
         register_projector_elements(get_projector_elements())
@@ -27,14 +28,14 @@ class AssignmentsAppConfig(AppConfig):
         permission_change.connect(
             get_permission_change_data,
             dispatch_uid='assignments_get_permission_change_data')
-        user_data_required.connect(
-            required_users,
-            dispatch_uid='assignments_required_users')
 
         # Register viewsets.
         router.register(self.get_model('Assignment').get_collection_string(), AssignmentViewSet)
         router.register('assignments/poll', AssignmentPollViewSet)
 
+        # Register required_users
+        required_user.add_collection_string(self.get_model('Assignment').get_collection_string(), required_users)
+
     def get_config_variables(self):
         from .config_variables import get_config_variables
         return get_config_variables()
@@ -56,3 +57,14 @@ class AssignmentsAppConfig(AppConfig):
                 'display_name': phase[1],
             })
         return {'AssignmentPhases': phases}
+
+
+def required_users(element: Dict[str, Any]) -> Set[int]:
+    """
+    Returns all user ids that are displayed as candidates (including poll
+    options) in the assignment element.
+    """
+    candidates = set(related_user['user_id'] for related_user in element['assignment_related_users'])
+    for poll in element['polls']:
+        candidates.update(option['candidate_id'] for option in poll['options'])
+    return candidates
diff --git a/openslides/assignments/models.py b/openslides/assignments/models.py
index b970f8e56..53b894221 100644
--- a/openslides/assignments/models.py
+++ b/openslides/assignments/models.py
@@ -91,6 +91,7 @@ class Assignment(RESTModelMixin, models.Model):
     Model for assignments.
     """
     access_permissions = AssignmentAccessPermissions()
+    can_see_permission = 'assignments.can_see'
 
     objects = AssignmentManager()
 
diff --git a/openslides/assignments/signals.py b/openslides/assignments/signals.py
index 48bc9cdb8..22182ba51 100644
--- a/openslides/assignments/signals.py
+++ b/openslides/assignments/signals.py
@@ -1,11 +1,5 @@
-from typing import Any, Set
-
 from django.apps import apps
 
-from ..utils.auth import has_perm
-from ..utils.collection import Collection
-from .models import Assignment
-
 
 def get_permission_change_data(sender, permissions=None, **kwargs):
     """
@@ -16,19 +10,3 @@ def get_permission_change_data(sender, permissions=None, **kwargs):
         # There could be only one 'assignment.can_see' and then we want to return data.
         if permission.content_type.app_label == assignments_app.label and permission.codename == 'can_see':
             yield from assignments_app.get_startup_elements()
-
-
-def required_users(sender, request_user, **kwargs):
-    """
-    Returns all user ids that are displayed as candidates (including poll
-    options) in any assignment if request_user can see assignments. This
-    function may return an empty set.
-    """
-    candidates: Set[Any] = set()
-    if has_perm(request_user, 'assignments.can_see'):
-        for assignment_collection_element in Collection(Assignment.get_collection_string()).element_generator():
-            full_data = assignment_collection_element.get_full_data()
-            candidates.update(related_user['user_id'] for related_user in full_data['assignment_related_users'])
-            for poll in full_data['polls']:
-                candidates.update(option['candidate_id'] for option in poll['options'])
-    return candidates
diff --git a/openslides/core/access_permissions.py b/openslides/core/access_permissions.py
index d07368110..2e2276465 100644
--- a/openslides/core/access_permissions.py
+++ b/openslides/core/access_permissions.py
@@ -1,18 +1,11 @@
-from django.contrib.auth.models import AnonymousUser
-
 from ..utils.access_permissions import BaseAccessPermissions
-from ..utils.auth import anonymous_is_enabled, has_perm
 
 
 class ProjectorAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Projector and ProjectorViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'core.can_see_projector')
+    base_permission = 'core.can_see_projector'
 
     def get_serializer_class(self, user=None):
         """
@@ -27,13 +20,6 @@ class TagAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Tag and TagViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        # Every authenticated user can retrieve tags. Anonymous users can do
-        # so if they are enabled.
-        return not isinstance(user, AnonymousUser) or anonymous_is_enabled()
 
     def get_serializer_class(self, user=None):
         """
@@ -48,13 +34,7 @@ class ChatMessageAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for ChatMessage and ChatMessageViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        # Anonymous users can see the chat if the anonymous group has the
-        # permission core.can_use_chat. But they can not use it. See views.py.
-        return has_perm(user, 'core.can_use_chat')
+    base_permission = 'core.can_use_chat'
 
     def get_serializer_class(self, user=None):
         """
@@ -69,11 +49,7 @@ class ProjectorMessageAccessPermissions(BaseAccessPermissions):
     """
     Access permissions for ProjectorMessage.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'core.can_see_projector')
+    base_permission = 'core.can_see_projector'
 
     def get_serializer_class(self, user=None):
         """
@@ -88,11 +64,7 @@ class CountdownAccessPermissions(BaseAccessPermissions):
     """
     Access permissions for Countdown.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'core.can_see_projector')
+    base_permission = 'core.can_see_projector'
 
     def get_serializer_class(self, user=None):
         """
@@ -108,13 +80,6 @@ class ConfigAccessPermissions(BaseAccessPermissions):
     Access permissions container for the config (ConfigStore and
     ConfigViewSet).
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        # Every authenticated user can see the metadata and list or retrieve
-        # the config. Anonymous users can do so if they are enabled.
-        return not isinstance(user, AnonymousUser) or anonymous_is_enabled()
 
     def get_serializer_class(self, user=None):
         """
diff --git a/openslides/core/apps.py b/openslides/core/apps.py
index 1d85f4dd4..3b94070c6 100644
--- a/openslides/core/apps.py
+++ b/openslides/core/apps.py
@@ -1,6 +1,6 @@
 from collections import OrderedDict
 from operator import attrgetter
-from typing import Any, Dict, List
+from typing import Any, Dict, List, Set
 
 from django.apps import AppConfig
 from django.conf import settings
@@ -28,8 +28,6 @@ class CoreAppConfig(AppConfig):
             get_permission_change_data,
             permission_change,
             post_permission_creation,
-            required_users,
-            user_data_required,
         )
         from .views import (
             ChatMessageViewSet,
@@ -47,6 +45,7 @@ class CoreAppConfig(AppConfig):
             AutoupdateWebsocketClientMessage,
         )
         from ..utils.websocket import register_client_message
+        from ..utils.access_permissions import required_user
 
         # Collect all config variables before getting the constants.
         config.collect_config_variables_from_apps()
@@ -68,9 +67,6 @@ class CoreAppConfig(AppConfig):
         permission_change.connect(
             get_permission_change_data,
             dispatch_uid='core_get_permission_change_data')
-        user_data_required.connect(
-            required_users,
-            dispatch_uid='core_required_users')
 
         post_migrate.connect(call_save_default_values, sender=self, dispatch_uid='core_save_config_default_values')
 
@@ -95,6 +91,9 @@ class CoreAppConfig(AppConfig):
         register_client_message(GetElementsWebsocketClientMessage())
         register_client_message(AutoupdateWebsocketClientMessage())
 
+        # register required_users
+        required_user.add_collection_string(self.get_model('ChatMessage').get_collection_string(), required_users)
+
     def get_config_variables(self):
         from .config_variables import get_config_variables
         return get_config_variables()
@@ -154,3 +153,10 @@ class CoreAppConfig(AppConfig):
 def call_save_default_values(**kwargs):
     from .config import config
     config.save_default_values()
+
+
+def required_users(element: Dict[str, Any]) -> Set[int]:
+    """
+    Returns all user ids that are displayed as chatters.
+    """
+    return set(element['user_id'])
diff --git a/openslides/core/models.py b/openslides/core/models.py
index e80ef2f69..0c5af53f1 100644
--- a/openslides/core/models.py
+++ b/openslides/core/models.py
@@ -239,6 +239,7 @@ class ChatMessage(RESTModelMixin, models.Model):
     At the moment we only have one global chat room for managers.
     """
     access_permissions = ChatMessageAccessPermissions()
+    can_see_permission = 'core.can_use_chat'
 
     message = models.TextField()
 
diff --git a/openslides/core/signals.py b/openslides/core/signals.py
index 663b41852..f2a77e2f7 100644
--- a/openslides/core/signals.py
+++ b/openslides/core/signals.py
@@ -4,10 +4,6 @@ from django.contrib.contenttypes.models import ContentType
 from django.db.models import Q
 from django.dispatch import Signal
 
-from ..utils.auth import has_perm
-from ..utils.collection import Collection
-from .models import ChatMessage
-
 
 # This signal is send when the migrate command is done. That means it is sent
 # after post_migrate sending and creating all Permission objects. Don't use it
@@ -18,12 +14,6 @@ post_permission_creation = Signal()
 # permission). Connected receivers may yield Collections.
 permission_change = Signal()
 
-# This signal is sent if someone wants to see basic user data. Connected
-# receivers may answer a set of user ids that are required for the request
-# user (this can be anything that is allowd as argument for
-# utils.auth.has_perm()) e. g. as motion submitter or assignment candidate.
-user_data_required = Signal(providing_args=['request_user'])
-
 
 def delete_django_app_permissions(sender, **kwargs):
     """
@@ -51,16 +41,3 @@ def get_permission_change_data(sender, permissions, **kwargs):
                 yield core_app.get_model('Countdown')
             elif permission.codename == 'can_use_chat':
                 yield core_app.get_model('ChatMessage')
-
-
-def required_users(sender, request_user, **kwargs):
-    """
-    Returns all user ids that are displayed as chatters if request_user can
-    use the chat. This function may return an empty set.
-    """
-    chatters = set()
-    if has_perm(request_user, 'core.can_use_chat'):
-        for chat_message_collection_element in Collection(ChatMessage.get_collection_string()).element_generator():
-            full_data = chat_message_collection_element.get_full_data()
-            chatters.add(full_data['user_id'])
-    return chatters
diff --git a/openslides/core/websocket.py b/openslides/core/websocket.py
index 8c04d348c..d747e1611 100644
--- a/openslides/core/websocket.py
+++ b/openslides/core/websocket.py
@@ -45,7 +45,7 @@ class NotifyWebsocketClientMessage(BaseWebsocketClientMessage):
                 "type": "send_notify",
                 "incomming": content,
                 "senderReplyChannelName": consumer.channel_name,
-                "senderUserId": consumer.scope['user'].id or 0,
+                "senderUserId": consumer.scope['user'].id if consumer.scope['user'] else 0,
             },
         )
 
diff --git a/openslides/mediafiles/access_permissions.py b/openslides/mediafiles/access_permissions.py
index 93c84c8b4..461e75774 100644
--- a/openslides/mediafiles/access_permissions.py
+++ b/openslides/mediafiles/access_permissions.py
@@ -1,7 +1,7 @@
 from typing import Any, Dict, List, Optional
 
 from ..utils.access_permissions import BaseAccessPermissions
-from ..utils.auth import has_perm
+from ..utils.auth import async_has_perm
 from ..utils.collection import CollectionElement
 
 
@@ -9,11 +9,7 @@ class MediafileAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Mediafile and MediafileViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'mediafiles.can_see')
+    base_permission = 'mediafiles.can_see'
 
     def get_serializer_class(self, user=None):
         """
@@ -23,7 +19,7 @@ class MediafileAccessPermissions(BaseAccessPermissions):
 
         return MediafileSerializer
 
-    def get_restricted_data(
+    async def get_restricted_data(
             self,
             full_data: List[Dict[str, Any]],
             user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
@@ -32,9 +28,9 @@ class MediafileAccessPermissions(BaseAccessPermissions):
         for the user. Removes hidden mediafiles for  some users.
         """
         # Parse data.
-        if has_perm(user, 'mediafiles.can_see') and has_perm(user, 'mediafiles.can_see_hidden'):
+        if await async_has_perm(user, 'mediafiles.can_see') and await async_has_perm(user, 'mediafiles.can_see_hidden'):
             data = full_data
-        elif has_perm(user, 'mediafiles.can_see'):
+        elif await async_has_perm(user, 'mediafiles.can_see'):
             # Exclude hidden mediafiles.
             data = [full for full in full_data if not full['hidden']]
         else:
diff --git a/openslides/mediafiles/apps.py b/openslides/mediafiles/apps.py
index 90d16b3d3..a7c340310 100644
--- a/openslides/mediafiles/apps.py
+++ b/openslides/mediafiles/apps.py
@@ -1,3 +1,5 @@
+from typing import Any, Dict, Set
+
 from django.apps import AppConfig
 
 from ..utils.projector import register_projector_elements
@@ -11,11 +13,12 @@ class MediafilesAppConfig(AppConfig):
 
     def ready(self):
         # Import all required stuff.
-        from openslides.core.signals import permission_change, user_data_required
+        from openslides.core.signals import permission_change
         from openslides.utils.rest_api import router
         from .projector import get_projector_elements
-        from .signals import get_permission_change_data, required_users
+        from .signals import get_permission_change_data
         from .views import MediafileViewSet
+        from ..utils.access_permissions import required_user
 
         # Define projector elements.
         register_projector_elements(get_projector_elements())
@@ -24,16 +27,25 @@ class MediafilesAppConfig(AppConfig):
         permission_change.connect(
             get_permission_change_data,
             dispatch_uid='mediafiles_get_permission_change_data')
-        user_data_required.connect(
-            required_users,
-            dispatch_uid='mediafiles_required_users')
 
         # Register viewsets.
         router.register(self.get_model('Mediafile').get_collection_string(), MediafileViewSet)
 
+        # register required_users
+        required_user.add_collection_string(self.get_model('Mediafile').get_collection_string(), required_users)
+
     def get_startup_elements(self):
         """
         Yields all Cachables required on startup i. e. opening the websocket
         connection.
         """
         yield self.get_model('Mediafile')
+
+
+def required_users(element: Dict[str, Any]) -> Set[int]:
+    """
+    Returns all user ids that are displayed as uploaders in any mediafile
+    if request_user can see mediafiles. This function may return an empty
+    set.
+    """
+    return set(element['uploader_id'])
diff --git a/openslides/mediafiles/models.py b/openslides/mediafiles/models.py
index 043f1d5b5..c418ce6cf 100644
--- a/openslides/mediafiles/models.py
+++ b/openslides/mediafiles/models.py
@@ -14,6 +14,7 @@ class Mediafile(RESTModelMixin, models.Model):
     Class for uploaded files which can be delivered under a certain url.
     """
     access_permissions = MediafileAccessPermissions()
+    can_see_permission = 'mediafiles.can_see'
 
     mediafile = models.FileField(upload_to='file')
     """
diff --git a/openslides/mediafiles/signals.py b/openslides/mediafiles/signals.py
index 72d1c2f4c..ad297ac19 100644
--- a/openslides/mediafiles/signals.py
+++ b/openslides/mediafiles/signals.py
@@ -1,9 +1,5 @@
 from django.apps import apps
 
-from ..utils.auth import has_perm
-from ..utils.collection import Collection
-from .models import Mediafile
-
 
 def get_permission_change_data(sender, permissions=None, **kwargs):
     """
@@ -14,17 +10,3 @@ def get_permission_change_data(sender, permissions=None, **kwargs):
         # There could be only one 'mediafiles.can_see' and then we want to return data.
         if permission.content_type.app_label == mediafiles_app.label and permission.codename == 'can_see':
             yield from mediafiles_app.get_startup_elements()
-
-
-def required_users(sender, request_user, **kwargs):
-    """
-    Returns all user ids that are displayed as uploaders in any mediafile
-    if request_user can see mediafiles. This function may return an empty
-    set.
-    """
-    uploaders = set()
-    if has_perm(request_user, 'mediafiles.can_see'):
-        for mediafile_collection_element in Collection(Mediafile.get_collection_string()).element_generator():
-            full_data = mediafile_collection_element.get_full_data()
-            uploaders.add(full_data['uploader_id'])
-    return uploaders
diff --git a/openslides/motions/access_permissions.py b/openslides/motions/access_permissions.py
index 3af2d2f58..069cadadc 100644
--- a/openslides/motions/access_permissions.py
+++ b/openslides/motions/access_permissions.py
@@ -2,7 +2,7 @@ from copy import deepcopy
 from typing import Any, Dict, List, Optional
 
 from ..utils.access_permissions import BaseAccessPermissions
-from ..utils.auth import has_perm, in_some_groups
+from ..utils.auth import async_has_perm, async_in_some_groups
 from ..utils.collection import CollectionElement
 
 
@@ -10,11 +10,7 @@ class MotionAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Motion and MotionViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'motions.can_see')
+    base_permission = 'motions.can_see'
 
     def get_serializer_class(self, user=None):
         """
@@ -24,7 +20,7 @@ class MotionAccessPermissions(BaseAccessPermissions):
 
         return MotionSerializer
 
-    def get_restricted_data(
+    async def get_restricted_data(
             self,
             full_data: List[Dict[str, Any]],
             user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
@@ -36,7 +32,7 @@ class MotionAccessPermissions(BaseAccessPermissions):
         personal notes.
         """
         # Parse data.
-        if has_perm(user, 'motions.can_see'):
+        if await async_has_perm(user, 'motions.can_see'):
             # TODO: Refactor this after personal_notes system is refactored.
             data = []
             for full in full_data:
@@ -52,8 +48,8 @@ class MotionAccessPermissions(BaseAccessPermissions):
                 required_permission_to_see = full['state_required_permission_to_see']
                 permission = (
                     not required_permission_to_see or
-                    has_perm(user, required_permission_to_see) or
-                    has_perm(user, 'motions.can_manage') or
+                    await async_has_perm(user, required_permission_to_see) or
+                    await async_has_perm(user, 'motions.can_manage') or
                     is_submitter)
 
                 # Parse single motion.
@@ -61,7 +57,7 @@ class MotionAccessPermissions(BaseAccessPermissions):
                     full_copy = deepcopy(full)
                     full_copy['comments'] = []
                     for comment in full['comments']:
-                        if in_some_groups(user, comment['read_groups_id']):
+                        if await async_in_some_groups(user, comment['read_groups_id']):
                             full_copy['comments'].append(comment)
                     data.append(full_copy)
         else:
@@ -74,11 +70,7 @@ class MotionChangeRecommendationAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for MotionChangeRecommendation and MotionChangeRecommendationViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'motions.can_see')
+    base_permission = 'motions.can_see'
 
     def get_serializer_class(self, user=None):
         """
@@ -88,7 +80,7 @@ class MotionChangeRecommendationAccessPermissions(BaseAccessPermissions):
 
         return MotionChangeRecommendationSerializer
 
-    def get_restricted_data(
+    async def get_restricted_data(
             self,
             full_data: List[Dict[str, Any]],
             user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
@@ -98,8 +90,8 @@ class MotionChangeRecommendationAccessPermissions(BaseAccessPermissions):
         the can_see permission.
         """
         # Parse data.
-        if has_perm(user, 'motions.can_see'):
-            has_manage_perms = has_perm(user, 'motion.can_manage')
+        if await async_has_perm(user, 'motions.can_see'):
+            has_manage_perms = await async_has_perm(user, 'motion.can_manage')
             data = []
             for full in full_data:
                 if not full['internal'] or has_manage_perms:
@@ -114,11 +106,7 @@ class MotionCommentSectionAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for MotionCommentSection and MotionCommentSectionViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'motions.can_see')
+    base_permission = 'motions.can_see'
 
     def get_serializer_class(self, user=None):
         """
@@ -128,7 +116,7 @@ class MotionCommentSectionAccessPermissions(BaseAccessPermissions):
 
         return MotionCommentSectionSerializer
 
-    def get_restricted_data(
+    async def get_restricted_data(
             self,
             full_data: List[Dict[str, Any]],
             user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
@@ -137,12 +125,12 @@ class MotionCommentSectionAccessPermissions(BaseAccessPermissions):
         will be removed, when the user is not in at least one of the read_groups.
         """
         data: List[Dict[str, Any]] = []
-        if has_perm(user, 'motions.can_manage'):
+        if await async_has_perm(user, 'motions.can_manage'):
             data = full_data
         else:
             for full in full_data:
                 read_groups = full.get('read_groups_id', [])
-                if in_some_groups(user, read_groups):
+                if await async_in_some_groups(user, read_groups):
                     data.append(full)
         return data
 
@@ -151,11 +139,7 @@ class StatuteParagraphAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for StatuteParagraph and StatuteParagraphViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'motions.can_see')
+    base_permission = 'motions.can_see'
 
     def get_serializer_class(self, user=None):
         """
@@ -170,11 +154,7 @@ class CategoryAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Category and CategoryViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'motions.can_see')
+    base_permission = 'motions.can_see'
 
     def get_serializer_class(self, user=None):
         """
@@ -189,11 +169,7 @@ class MotionBlockAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Category and CategoryViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'motions.can_see')
+    base_permission = 'motions.can_see'
 
     def get_serializer_class(self, user=None):
         """
@@ -208,11 +184,7 @@ class WorkflowAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Workflow and WorkflowViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'motions.can_see')
+    base_permission = 'motions.can_see'
 
     def get_serializer_class(self, user=None):
         """
diff --git a/openslides/motions/apps.py b/openslides/motions/apps.py
index c5ee14299..7ce32bdeb 100644
--- a/openslides/motions/apps.py
+++ b/openslides/motions/apps.py
@@ -1,3 +1,5 @@
+from typing import Any, Dict, Set
+
 from django.apps import AppConfig
 from django.db.models.signals import post_migrate
 
@@ -12,13 +14,12 @@ class MotionsAppConfig(AppConfig):
 
     def ready(self):
         # Import all required stuff.
-        from openslides.core.signals import permission_change, user_data_required
+        from openslides.core.signals import permission_change
         from openslides.utils.rest_api import router
         from .projector import get_projector_elements
         from .signals import (
             create_builtin_workflows,
             get_permission_change_data,
-            required_users,
         )
         from .views import (
             CategoryViewSet,
@@ -31,6 +32,7 @@ class MotionsAppConfig(AppConfig):
             StateViewSet,
             WorkflowViewSet,
         )
+        from ..utils.access_permissions import required_user
 
         # Define projector elements.
         register_projector_elements(get_projector_elements())
@@ -42,9 +44,6 @@ class MotionsAppConfig(AppConfig):
         permission_change.connect(
             get_permission_change_data,
             dispatch_uid='motions_get_permission_change_data')
-        user_data_required.connect(
-            required_users,
-            dispatch_uid='motions_required_users')
 
         # Register viewsets.
         router.register(self.get_model('Category').get_collection_string(), CategoryViewSet)
@@ -58,6 +57,9 @@ class MotionsAppConfig(AppConfig):
         router.register(self.get_model('MotionPoll').get_collection_string(), MotionPollViewSet)
         router.register(self.get_model('State').get_collection_string(), StateViewSet)
 
+        # Register required_users
+        required_user.add_collection_string(self.get_model('Motion').get_collection_string(), required_users)
+
     def get_config_variables(self):
         from .config_variables import get_config_variables
         return get_config_variables()
@@ -70,3 +72,14 @@ class MotionsAppConfig(AppConfig):
         for model_name in ('Category', 'StatuteParagraph', 'Motion', 'MotionBlock',
                            'Workflow', 'MotionChangeRecommendation', 'MotionCommentSection'):
             yield self.get_model(model_name)
+
+
+def required_users(element: Dict[str, Any]) -> Set[int]:
+    """
+    Returns all user ids that are displayed as as submitter or supporter in
+    any motion if request_user can see motions. This function may return an
+    empty set.
+    """
+    submitters_supporters = set([submitter['user_id'] for submitter in element['submitters']])
+    submitters_supporters.update(element['supporters_id'])
+    return submitters_supporters
diff --git a/openslides/motions/models.py b/openslides/motions/models.py
index 1ff79ee67..c6098dd16 100644
--- a/openslides/motions/models.py
+++ b/openslides/motions/models.py
@@ -93,6 +93,7 @@ class Motion(RESTModelMixin, models.Model):
     This class is the main entry point to all other classes related to a motion.
     """
     access_permissions = MotionAccessPermissions()
+    can_see_permission = 'motions.can_see'
 
     objects = MotionManager()
 
diff --git a/openslides/motions/signals.py b/openslides/motions/signals.py
index e7abc8032..3e7383612 100644
--- a/openslides/motions/signals.py
+++ b/openslides/motions/signals.py
@@ -1,11 +1,7 @@
-from typing import Set
-
 from django.apps import apps
 from django.utils.translation import ugettext_noop
 
-from ..utils.auth import has_perm
-from ..utils.collection import Collection
-from .models import Motion, State, Workflow
+from .models import State, Workflow
 
 
 def create_builtin_workflows(sender, **kwargs):
@@ -108,19 +104,3 @@ def get_permission_change_data(sender, permissions, **kwargs):
         # There could be only one 'motions.can_see' and then we want to return data.
         if permission.content_type.app_label == motions_app.label and permission.codename == 'can_see':
             yield from motions_app.get_startup_elements()
-
-
-def required_users(sender, request_user, **kwargs):
-    """
-    Returns all user ids that are displayed as as submitter or supporter in
-    any motion if request_user can see motions. This function may return an
-    empty set.
-    """
-    submitters_supporters: Set[int] = set()
-    if has_perm(request_user, 'motions.can_see'):
-        for motion_collection_element in Collection(Motion.get_collection_string()).element_generator():
-            full_data = motion_collection_element.get_full_data()
-            submitters_supporters.update(
-                [submitter['user_id'] for submitter in full_data['submitters']])
-            submitters_supporters.update(full_data['supporters_id'])
-    return submitters_supporters
diff --git a/openslides/topics/access_permissions.py b/openslides/topics/access_permissions.py
index ec9696b7a..49a254a73 100644
--- a/openslides/topics/access_permissions.py
+++ b/openslides/topics/access_permissions.py
@@ -1,16 +1,11 @@
 from ..utils.access_permissions import BaseAccessPermissions
-from ..utils.auth import has_perm
 
 
 class TopicAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Topic and TopicViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        return has_perm(user, 'agenda.can_see')
+    base_permission = 'agenda.can_see'
 
     def get_serializer_class(self, user=None):
         """
diff --git a/openslides/users/access_permissions.py b/openslides/users/access_permissions.py
index a7ce3cac4..b6fc27848 100644
--- a/openslides/users/access_permissions.py
+++ b/openslides/users/access_permissions.py
@@ -1,22 +1,17 @@
-from typing import Any, Dict, List, Optional
+from typing import Any, Dict, List, Optional, Set
 
-from django.contrib.auth.models import AnonymousUser
-
-from ..core.signals import user_data_required
-from ..utils.access_permissions import BaseAccessPermissions
-from ..utils.auth import anonymous_is_enabled, has_perm
-from ..utils.collection import CollectionElement
+from ..utils.access_permissions import BaseAccessPermissions, required_user
+from ..utils.auth import async_has_perm
+from ..utils.collection import (
+    CollectionElement,
+    get_model_from_collection_string,
+)
 
 
 class UserAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for User and UserViewSet.
     """
-    def check_permissions(self, user):
-        """
-        Every user has read access for their model instnces.
-        """
-        return True
 
     def get_serializer_class(self, user=None):
         """
@@ -26,7 +21,7 @@ class UserAccessPermissions(BaseAccessPermissions):
 
         return UserFullSerializer
 
-    def get_restricted_data(
+    async def get_restricted_data(
             self,
             full_data: List[Dict[str, Any]],
             user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
@@ -62,9 +57,9 @@ class UserAccessPermissions(BaseAccessPermissions):
         litte_data_fields.discard('groups')
 
         # Check user permissions.
-        if has_perm(user, 'users.can_see_name'):
-            if has_perm(user, 'users.can_see_extra_data'):
-                if has_perm(user, 'users.can_manage'):
+        if await async_has_perm(user, 'users.can_see_name'):
+            if await async_has_perm(user, 'users.can_see_extra_data'):
+                if await async_has_perm(user, 'users.can_manage'):
                     data = [filtered_data(full, all_data_fields) for full in full_data]
                 else:
                     data = [filtered_data(full, many_data_fields) for full in full_data]
@@ -73,23 +68,21 @@ class UserAccessPermissions(BaseAccessPermissions):
         else:
             # Build a list of users, that can be seen without any permissions (with little fields).
 
-            user_ids = set()
-
             # Everybody can see himself. Also everybody can see every user
             # that is required e. g. as speaker, motion submitter or
             # assignment candidate.
 
+            can_see_collection_strings: Set[str] = set()
+            for collection_string in required_user.get_collection_strings():
+                if await async_has_perm(user, get_model_from_collection_string(collection_string).can_see_permission):
+                    can_see_collection_strings.add(collection_string)
+
+            user_ids = await required_user.get_required_users(can_see_collection_strings)
+
             # Add oneself.
             if user is not None:
                 user_ids.add(user.id)
 
-            # Get a list of all users, that are required by another app.
-            receiver_responses = user_data_required.send(
-                sender=self.__class__,
-                request_user=user)
-            for receiver, response in receiver_responses:
-                user_ids.update(response)
-
             # Parse data.
             data = [
                 filtered_data(full, litte_data_fields)
@@ -104,13 +97,6 @@ class GroupAccessPermissions(BaseAccessPermissions):
     """
     Access permissions container for Groups. Everyone can see them
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        # Every authenticated user can retrieve groups. Anonymous users can do
-        # so if they are enabled.
-        return not isinstance(user, AnonymousUser) or anonymous_is_enabled()
 
     def get_serializer_class(self, user=None):
         """
@@ -126,12 +112,6 @@ class PersonalNoteAccessPermissions(BaseAccessPermissions):
     Access permissions container for personal notes. Every authenticated user
     can handle personal notes.
     """
-    def check_permissions(self, user):
-        """
-        Returns True if the user has read access model instances.
-        """
-        # Every authenticated user can retrieve personal notes.
-        return not isinstance(user, AnonymousUser)
 
     def get_serializer_class(self, user=None):
         """
@@ -141,7 +121,7 @@ class PersonalNoteAccessPermissions(BaseAccessPermissions):
 
         return PersonalNoteSerializer
 
-    def get_restricted_data(
+    async def get_restricted_data(
             self,
             full_data: List[Dict[str, Any]],
             user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
diff --git a/openslides/users/views.py b/openslides/users/views.py
index 84fa779bf..bdf4fe6bc 100644
--- a/openslides/users/views.py
+++ b/openslides/users/views.py
@@ -30,7 +30,7 @@ from ..utils.autoupdate import (
     inform_data_collection_element_list,
 )
 from ..utils.cache import element_cache
-from ..utils.collection import Collection, CollectionElement
+from ..utils.collection import CollectionElement
 from ..utils.rest_api import (
     ModelViewSet,
     Response,
@@ -329,9 +329,11 @@ class GroupViewSet(ModelViewSet):
             if len(new_permissions) > 0:
                 collection_elements: List[CollectionElement] = []
                 signal_results = permission_change.send(None, permissions=new_permissions, action='added')
+                all_full_data = async_to_sync(element_cache.get_all_full_data)()
                 for receiver, signal_collections in signal_results:
                     for cachable in signal_collections:
-                        collection_elements.extend(Collection(cachable.get_collection_string()).element_generator())
+                        for element in all_full_data.get(cachable.get_collection_string(), {}):
+                            collection_elements.append(CollectionElement.from_values(cachable.get_collection_string(), element['id']))
                 inform_data_collection_element_list(collection_elements)
 
             # TODO: Some permissions are deleted.
@@ -462,8 +464,10 @@ class UserLoginView(APIView):
         else:
             # self.request.method == 'POST'
             context['user_id'] = self.user.pk
-            user_collection = CollectionElement.from_instance(self.user)
-            context['user'] = user_collection.as_dict_for_user(self.user)
+            context['user'] = async_to_sync(element_cache.get_element_restricted_data)(
+                CollectionElement.from_instance(self.user),
+                self.user.get_collection_string(),
+                self.user.pk)
         return super().get_context_data(**context)
 
 
@@ -494,8 +498,10 @@ class WhoAmIView(APIView):
         """
         user_id = self.request.user.pk
         if user_id is not None:
-            user_collection = CollectionElement.from_instance(self.request.user)
-            user_data = user_collection.as_dict_for_user(self.request.user)
+            user_data = async_to_sync(element_cache.get_element_restricted_data)(
+                user_to_collection_user(self.request.user),
+                self.request.user.get_collection_string(),
+                user_id)
         else:
             user_data = None
         return super().get_context_data(
diff --git a/openslides/utils/access_permissions.py b/openslides/utils/access_permissions.py
index 309aec9ff..14e49dae5 100644
--- a/openslides/utils/access_permissions.py
+++ b/openslides/utils/access_permissions.py
@@ -1,8 +1,15 @@
-from typing import Any, Dict, List, Optional
+from typing import Any, Callable, Dict, List, Optional, Set
 
+from asgiref.sync import async_to_sync
 from django.db.models import Model
 from rest_framework.serializers import Serializer
 
+from .auth import (
+    async_anonymous_is_enabled,
+    async_has_perm,
+    user_to_collection_user,
+)
+from .cache import element_cache
 from .collection import CollectionElement
 
 
@@ -14,11 +21,30 @@ class BaseAccessPermissions:
     from this base class for every autoupdate root model.
     """
 
+    base_permission = ''
+    """
+    Set to a permission the user needs to see the element.
+
+    If this string is empty, all users can see it.
+    """
+
     def check_permissions(self, user: Optional[CollectionElement]) -> bool:
         """
         Returns True if the user has read access to model instances.
         """
-        return False
+        # Convert user to right type
+        # TODO: Remove this and make sure, that user has always the right type
+        user = user_to_collection_user(user)
+        return async_to_sync(self.async_check_permissions)(user)
+
+    async def async_check_permissions(self, user: Optional[CollectionElement]) -> bool:
+        """
+        Returns True if the user has read access to model instances.
+        """
+        if self.base_permission:
+            return await async_has_perm(user, self.base_permission)
+        else:
+            return user is not None or await async_anonymous_is_enabled()
 
     def get_serializer_class(self, user: CollectionElement = None) -> Serializer:
         """
@@ -37,7 +63,7 @@ class BaseAccessPermissions:
         """
         return self.get_serializer_class(user=None)(instance).data
 
-    def get_restricted_data(
+    async def get_restricted_data(
             self, full_data: List[Dict[str, Any]],
             user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
         """
@@ -55,4 +81,51 @@ class BaseAccessPermissions:
         have access restrictions in your view or viewset in methods like
         retrieve() or list().
         """
-        return full_data if self.check_permissions(user) else []
+        return full_data if await self.async_check_permissions(user) else []
+
+
+class RequiredUsers:
+    """
+    Helper class to find all users that are required by another element.
+    """
+
+    callables: Dict[str, Callable[[Dict[str, Any]], Set[int]]] = {}
+
+    def get_collection_strings(self) -> Set[str]:
+        """
+        Returns all collection strings for elements that could have required users.
+        """
+        return set(self.callables.keys())
+
+    def add_collection_string(self, collection_string: str, callable: Callable[[Dict[str, Any]], Set[int]]) -> None:
+        """
+        Add a callable for a collection_string to get the required users of the
+        elements.
+        """
+        self.callables[collection_string] = callable
+
+    async def get_required_users(self, collection_strings: Set[str]) -> Set[int]:
+        """
+        Returns the user ids that are required by other elements.
+
+        Returns only user ids required by elements with a collection_string
+        in the argument collection_strings.
+        """
+        user_ids: Set[int] = set()
+
+        all_full_data = await element_cache.get_all_full_data()
+        for collection_string in collection_strings:
+            # Get the callable for the collection_string
+            get_user_ids = self.callables.get(collection_string)
+            elements = all_full_data.get(collection_string, {})
+            if not (get_user_ids and elements):
+                # if the collection_string is unknown or it has no data, do nothing
+                continue
+
+            for element in elements:
+                user_ids.update(get_user_ids(element))
+
+        return user_ids
+
+
+required_user = RequiredUsers()
diff --git a/openslides/utils/auth.py b/openslides/utils/auth.py
index a957907e4..5cb5e73b9 100644
--- a/openslides/utils/auth.py
+++ b/openslides/utils/auth.py
@@ -1,5 +1,6 @@
 from typing import Dict, List, Optional, Union, cast
 
+from asgiref.sync import async_to_sync
 from django.apps import apps
 from django.conf import settings
 from django.contrib.auth import get_user_model
@@ -35,17 +36,28 @@ def has_perm(user: Optional[CollectionElement], perm: str) -> bool:
 
     User can be a CollectionElement of a user or None.
     """
-    group_collection_string = 'users/group'  # This is the hard coded collection string for openslides.users.models.Group
-
     # Convert user to right type
     # TODO: Remove this and make use, that user has always the right type
     user = user_to_collection_user(user)
-    if user is None and not anonymous_is_enabled():
+    return async_to_sync(async_has_perm)(user, perm)
+
+
+async def async_has_perm(user: Optional[CollectionElement], perm: str) -> bool:
+    """
+    Checks that user has a specific permission.
+
+    User can be a CollectionElement of a user or None.
+    """
+    group_collection_string = 'users/group'  # This is the hard coded collection string for openslides.users.models.Group
+
+    if user is None and not await async_anonymous_is_enabled():
         has_perm = False
     elif user is None:
         # Use the permissions from the default group.
-        default_group = CollectionElement.from_values(group_collection_string, GROUP_DEFAULT_PK)
-        has_perm = perm in default_group.get_full_data()['permissions']
+        default_group = await element_cache.get_element_full_data(group_collection_string, GROUP_DEFAULT_PK)
+        if default_group is None:
+            raise RuntimeError('Default Group does not exist.')
+        has_perm = perm in default_group['permissions']
     elif GROUP_ADMIN_PK in user.get_full_data()['groups_id']:
         # User in admin group (pk 2) grants all permissions.
         has_perm = True
@@ -54,8 +66,11 @@ def has_perm(user: Optional[CollectionElement], perm: str) -> bool:
         # permission. If the user has no groups, then use the default group.
         group_ids = user.get_full_data()['groups_id'] or [GROUP_DEFAULT_PK]
         for group_id in group_ids:
-            group = CollectionElement.from_values(group_collection_string, group_id)
-            if perm in group.get_full_data()['permissions']:
+            group = await element_cache.get_element_full_data(group_collection_string, group_id)
+            if group is None:
+                raise RuntimeError('User is in non existing group with id {}.'.format(group_id))
+
+            if perm in group['permissions']:
                 has_perm = True
                 break
         else:
@@ -78,7 +93,22 @@ def in_some_groups(user: Optional[CollectionElement], groups: List[int]) -> bool
     # Convert user to right type
     # TODO: Remove this and make use, that user has always the right type
     user = user_to_collection_user(user)
-    if user is None and not anonymous_is_enabled():
+    return async_to_sync(async_in_some_groups)(user, groups)
+
+
+async def async_in_some_groups(user: Optional[CollectionElement], groups: List[int]) -> bool:
+    """
+    Checks that user is in at least one given group. Groups can be given as a list
+    of ids. If the user is in the admin group (pk = 2) the result
+    is always true.
+
+    User can be a CollectionElement of a user or None.
+    """
+
+    if not len(groups):
+        return False  # early end here, if no groups are given.
+
+    if user is None and not await async_anonymous_is_enabled():
         in_some_groups = False
     elif user is None:
         # Use the permissions from the default group.
diff --git a/openslides/utils/cache.py b/openslides/utils/cache.py
index 46f4df3cf..0e216334b 100644
--- a/openslides/utils/cache.py
+++ b/openslides/utils/cache.py
@@ -14,7 +14,7 @@ from typing import (
     Type,
 )
 
-from asgiref.sync import async_to_sync, sync_to_async
+from asgiref.sync import async_to_sync
 from django.conf import settings
 
 from .cache_providers import (
@@ -23,8 +23,8 @@ from .cache_providers import (
     MemmoryCacheProvider,
     RedisCacheProvider,
     get_all_cachables,
-    no_redis_dependency,
 )
+from .redis import use_redis
 from .utils import get_element_id, get_user_id, split_element_id
 
 
@@ -60,7 +60,6 @@ class ElementCache:
 
     def __init__(
             self,
-            redis: str,
             use_restricted_data_cache: bool = False,
             cache_provider_class: Type[ElementCacheProvider] = RedisCacheProvider,
             cachable_provider: Callable[[], List[Cachable]] = get_all_cachables,
@@ -71,7 +70,7 @@ class ElementCache:
         When restricted_data_cache is false, no restricted data is saved.
         """
         self.use_restricted_data_cache = use_restricted_data_cache
-        self.cache_provider = cache_provider_class(redis)
+        self.cache_provider = cache_provider_class()
         self.cachable_provider = cachable_provider
         self._cachables: Optional[Dict[str, Cachable]] = None
 
@@ -210,8 +209,6 @@ class ElementCache:
         """
         Returns one element as full data.
 
-        If the cache is empty, it is created.
-
         Returns None if the element does not exist.
         """
         element = await self.cache_provider.get_element(get_element_id(collection_string, id))
@@ -276,7 +273,7 @@ class ElementCache:
                 mapping = {}
                 for collection_string, full_data in full_data_elements.items():
                     restricter = self.cachables[collection_string].restrict_elements
-                    elements = await sync_to_async(restricter)(user, full_data)
+                    elements = await restricter(user, full_data)
                     for element in elements:
                         mapping.update(
                             {get_element_id(collection_string, element['id']):
@@ -303,7 +300,7 @@ class ElementCache:
             all_restricted_data = {}
             for collection_string, full_data in (await self.get_all_full_data()).items():
                 restricter = self.cachables[collection_string].restrict_elements
-                elements = await sync_to_async(restricter)(user, full_data)
+                elements = await restricter(user, full_data)
                 all_restricted_data[collection_string] = elements
             return all_restricted_data
 
@@ -335,7 +332,7 @@ class ElementCache:
             restricted_data = {}
             for collection_string, full_data in changed_elements.items():
                 restricter = self.cachables[collection_string].restrict_elements
-                elements = await sync_to_async(restricter)(user, full_data)
+                elements = await restricter(user, full_data)
                 restricted_data[collection_string] = elements
             return restricted_data, deleted_elements
 
@@ -358,6 +355,25 @@ class ElementCache:
              for collection_string, value_list in raw_changed_elements.items()},
             deleted_elements)
 
+    async def get_element_restricted_data(self, user: Optional['CollectionElement'], collection_string: str, id: int) -> Optional[Dict[str, Any]]:
+        """
+        Returns the restricted_data of one element.
+
+        Returns None, if the element does not exists or the user has no permission to see it.
+        """
+        if not self.use_restricted_data_cache:
+            full_data = await self.get_element_full_data(collection_string, id)
+            if full_data is None:
+                return None
+            restricter = self.cachables[collection_string].restrict_elements
+            restricted_data = await restricter(user, [full_data])
+            return restricted_data[0] if restricted_data else None
+
+        await self.update_restricted_data(user)
+
+        out = await self.cache_provider.get_element(get_element_id(collection_string, id), get_user_id(user))
+        return json.loads(out.decode()) if out else None
+
     async def get_current_change_id(self) -> int:
         """
         Returns the current change id.
@@ -383,19 +399,18 @@ class ElementCache:
         return value
 
 
-def load_element_cache(redis_addr: str = '', restricted_data: bool = True) -> ElementCache:
+def load_element_cache(restricted_data: bool = True) -> ElementCache:
     """
     Generates an element cache instance.
     """
-    if not redis_addr:
-        return ElementCache(redis='', cache_provider_class=MemmoryCacheProvider)
+    if use_redis:
+        cache_provider_class: Type[ElementCacheProvider] = RedisCacheProvider
+    else:
+        cache_provider_class = MemmoryCacheProvider
 
-    if no_redis_dependency:
-        raise ImportError("OpenSlides is configured to use redis as cache backend, but aioredis is not installed.")
-    return ElementCache(redis=redis_addr, use_restricted_data_cache=restricted_data)
+    return ElementCache(cache_provider_class=cache_provider_class, use_restricted_data_cache=restricted_data)
 
 
 # Set the element_cache
-redis_address = getattr(settings, 'REDIS_ADDRESS', '')
 use_restricted_data = getattr(settings, 'RESTRICTED_DATA_CACHE', True)
-element_cache = load_element_cache(redis_addr=redis_address, restricted_data=use_restricted_data)
+element_cache = load_element_cache(restricted_data=use_restricted_data)
diff --git a/openslides/utils/cache_providers.py b/openslides/utils/cache_providers.py
index f5962bd55..869c1202d 100644
--- a/openslides/utils/cache_providers.py
+++ b/openslides/utils/cache_providers.py
@@ -13,20 +13,18 @@ from typing import (
 from django.apps import apps
 from typing_extensions import Protocol
 
+from .redis import use_redis
 from .utils import split_element_id, str_dict_to_bytes
 
 
+if use_redis:
+    from .redis import get_connection, aioredis
+
+
 if TYPE_CHECKING:
     # Dummy import Collection for mypy, can be fixed with python 3.7
     from .collection import CollectionElement  # noqa
 
-try:
-    import aioredis
-except ImportError:
-    no_redis_dependency = True
-else:
-    no_redis_dependency = False
-
 
 class ElementCacheProvider(Protocol):
     """
@@ -35,8 +33,6 @@ class ElementCacheProvider(Protocol):
     See RedisCacheProvider as reverence implementation.
     """
 
-    def __init__(self, *args: Any) -> None: ...
-
     async def clear_cache(self) -> None: ...
 
     async def reset_full_cache(self, data: Dict[str, str]) -> None: ...
@@ -57,7 +53,7 @@ class ElementCacheProvider(Protocol):
             user_id: Optional[int] = None,
             max_change_id: int = -1) -> Tuple[Dict[str, List[bytes]], List[str]]: ...
 
-    async def get_element(self, element_id: str) -> Optional[bytes]: ...
+    async def get_element(self, element_id: str, user_id: Optional[int] = None) -> Optional[bytes]: ...
 
     async def del_restricted_data(self, user_id: int) -> None: ...
 
@@ -76,42 +72,15 @@ class ElementCacheProvider(Protocol):
     async def get_lowest_change_id(self) -> Optional[int]: ...
 
 
-class RedisConnectionContextManager:
-    """
-    Async context manager for connections
-    """
-    # TODO: contextlib.asynccontextmanager can be used in python 3.7
-
-    def __init__(self, redis_address: str) -> None:
-        self.redis_address = redis_address
-
-    async def __aenter__(self) -> 'aioredis.RedisConnection':
-        self.conn = await aioredis.create_redis(self.redis_address)
-        return self.conn
-
-    async def __aexit__(self, exc_type: Any, exc: Any, tb: Any) -> None:
-        self.conn.close()
-
-
 class RedisCacheProvider:
     """
     Cache provider that loads and saves the data to redis.
     """
-    redis_pool: Optional[aioredis.RedisConnection] = None
     full_data_cache_key: str = 'full_data'
     restricted_user_cache_key: str = 'restricted_data:{user_id}'
     change_id_cache_key: str = 'change_id'
     prefix: str = 'element_cache_'
 
-    def __init__(self, redis: str) -> None:
-        self.redis_address = redis
-
-    def get_connection(self) -> RedisConnectionContextManager:
-        """
-        Returns contextmanager for a redis connection.
-        """
-        return RedisConnectionContextManager(self.redis_address)
-
     def get_full_data_cache_key(self) -> str:
         return "".join((self.prefix, self.full_data_cache_key))
 
@@ -125,14 +94,14 @@ class RedisCacheProvider:
         """
         Deleted all cache entries created with this element cache.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             await redis.eval("return redis.call('del', 'fake_key', unpack(redis.call('keys', ARGV[1])))", keys=[], args=["{}*".format(self.prefix)])
 
     async def reset_full_cache(self, data: Dict[str, str]) -> None:
         """
         Deletes the full_data_cache and write new data in it.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             tr = redis.multi_exec()
             tr.delete(self.get_full_data_cache_key())
             tr.hmset_dict(self.get_full_data_cache_key(), data)
@@ -145,7 +114,7 @@ class RedisCacheProvider:
         If user_id is None, the method tests for full_data. If user_id is an int, it tests
         for the restricted_data_cache for the user with the user_id. 0 is for anonymous.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             if user_id is None:
                 cache_key = self.get_full_data_cache_key()
             else:
@@ -159,7 +128,7 @@ class RedisCacheProvider:
         elements is a list with an even len. the odd values are the element_ids and the even
         values are the elements. The elements have to be encoded, for example with json.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             await redis.hmset(
                 self.get_full_data_cache_key(),
                 *elements)
@@ -173,7 +142,7 @@ class RedisCacheProvider:
         If user_id is None, the elements are deleted from the full_data cache. If user_id is an
         int, the elements are deleted one restricted_data_cache. 0 is for anonymous.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             if user_id is None:
                 cache_key = self.get_full_data_cache_key()
             else:
@@ -188,7 +157,7 @@ class RedisCacheProvider:
 
         Generates and returns the change_id.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             return int(await redis.eval(
                 lua_script_change_data,
                 keys=[self.get_change_id_cache_key()],
@@ -206,18 +175,24 @@ class RedisCacheProvider:
             cache_key = self.get_full_data_cache_key()
         else:
             cache_key = self.get_restricted_data_cache_key(user_id)
-        async with self.get_connection() as redis:
+
+        async with get_connection() as redis:
             return await redis.hgetall(cache_key)
 
-    async def get_element(self, element_id: str) -> Optional[bytes]:
+    async def get_element(self, element_id: str, user_id: Optional[int] = None) -> Optional[bytes]:
         """
-        Returns one element from the full_data_cache.
+        Returns one element from the cache.
 
         Returns None, when the element does not exist.
         """
-        async with self.get_connection() as redis:
+        if user_id is None:
+            cache_key = self.get_full_data_cache_key()
+        else:
+            cache_key = self.get_restricted_data_cache_key(user_id)
+
+        async with get_connection() as redis:
             return await redis.hget(
-                self.get_full_data_cache_key(),
+                cache_key,
                 element_id)
 
     async def get_data_since(
@@ -244,7 +219,7 @@ class RedisCacheProvider:
 
         # Convert max_change_id to a string. If its negative, use the string '+inf'
         redis_max_change_id = "+inf" if max_change_id < 0 else str(max_change_id)
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             # lua script that returns gets all element_ids from change_id_cache_key
             # and then uses each element_id on full_data or restricted_data.
             # It returns a list where the odd values are the change_id and the
@@ -282,7 +257,7 @@ class RedisCacheProvider:
         """
         Deletes all restricted_data for an user. 0 is for the anonymous user.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             await redis.delete(self.get_restricted_data_cache_key(user_id))
 
     async def set_lock(self, lock_name: str) -> bool:
@@ -294,14 +269,14 @@ class RedisCacheProvider:
         Returns False when the lock was already set.
         """
         # TODO: Improve lock. See: https://redis.io/topics/distlock
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             return await redis.setnx("{}lock_{}".format(self.prefix, lock_name), 1)
 
     async def get_lock(self, lock_name: str) -> bool:
         """
         Returns True, when the lock for the restricted_data of an user is set. Else False.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             return await redis.get("{}lock_{}".format(self.prefix, lock_name))
 
     async def del_lock(self, lock_name: str) -> None:
@@ -309,7 +284,7 @@ class RedisCacheProvider:
         Deletes the lock for the restricted_data of an user. Does nothing when the
         lock is not set.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             await redis.delete("{}lock_{}".format(self.prefix, lock_name))
 
     async def get_change_id_user(self, user_id: int) -> Optional[int]:
@@ -318,7 +293,7 @@ class RedisCacheProvider:
 
         This is the change_id where the restricted_data was last calculated.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             return await redis.hget(self.get_restricted_data_cache_key(user_id), '_config:change_id')
 
     async def update_restricted_data(self, user_id: int, data: Dict[str, str]) -> None:
@@ -328,14 +303,14 @@ class RedisCacheProvider:
         data has to be a dict where the key is an element_id and the value the (json-) encoded
         element.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             await redis.hmset_dict(self.get_restricted_data_cache_key(user_id), data)
 
     async def get_current_change_id(self) -> List[Tuple[str, int]]:
         """
         Get the highest change_id from redis.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             return await redis.zrevrangebyscore(
                 self.get_change_id_cache_key(),
                 withscores=True,
@@ -348,7 +323,7 @@ class RedisCacheProvider:
 
         Returns None if lowest score does not exist.
         """
-        async with self.get_connection() as redis:
+        async with get_connection() as redis:
             return await redis.zscore(
                 self.get_change_id_cache_key(),
                 '_config:lowest_change_id')
@@ -364,7 +339,7 @@ class MemmoryCacheProvider:
     When you use different processes they will use diffrent data.
     """
 
-    def __init__(self, *args: Any, **kwargs: Any) -> None:
+    def __init__(self) -> None:
         self.set_data_dicts()
 
     def set_data_dicts(self) -> None:
@@ -428,8 +403,13 @@ class MemmoryCacheProvider:
 
         return str_dict_to_bytes(cache_dict)
 
-    async def get_element(self, element_id: str) -> Optional[bytes]:
-        value = self.full_data.get(element_id, None)
+    async def get_element(self, element_id: str, user_id: Optional[int] = None) -> Optional[bytes]:
+        if user_id is None:
+            cache_dict = self.full_data
+        else:
+            cache_dict = self.restricted_data.get(user_id, {})
+
+        value = cache_dict.get(element_id, None)
         return value.encode() if value is not None else None
 
     async def get_data_since(
@@ -516,7 +496,7 @@ class Cachable(Protocol):
         Returns all elements of the cachable.
         """
 
-    def restrict_elements(
+    async def restrict_elements(
             self,
             user: Optional['CollectionElement'],
             elements: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
diff --git a/openslides/utils/collection.py b/openslides/utils/collection.py
index b7b3f08d9..917572dc0 100644
--- a/openslides/utils/collection.py
+++ b/openslides/utils/collection.py
@@ -85,15 +85,6 @@ class CollectionElement:
         return (self.collection_string == collection_element.collection_string and
                 self.id == collection_element.id)
 
-    def as_dict_for_user(self, user: Optional['CollectionElement']) -> Optional[Dict[str, Any]]:
-        """
-        Returns a dict with the data for a user. Can be used for the rest api.
-
-        Returns None if the user does not has the permission to see the element.
-        """
-        restricted_data = self.get_access_permissions().get_restricted_data([self.get_full_data()], user)
-        return restricted_data[0] if restricted_data else None
-
     def get_model(self) -> Type[Model]:
         """
         Returns the django model that is used for this collection.
@@ -106,20 +97,6 @@ class CollectionElement:
         """
         return self.get_model().get_access_permissions()
 
-    def get_element_from_db(self) -> Optional[Dict[str, Any]]:
-        # Hack for django 2.0 and channels 2.1 to stay in the same thread.
-        # This is needed for the tests.
-        try:
-            query = self.get_model().objects.get_full_queryset()
-        except AttributeError:
-            # If the model des not have to method get_full_queryset(), then use
-            # the default queryset from django.
-            query = self.get_model().objects
-        try:
-            return self.get_access_permissions().get_full_data(query.get(pk=self.id))
-        except self.get_model().DoesNotExist:
-            return None
-
     def get_full_data(self) -> Dict[str, Any]:
         """
         Returns the full_data of this collection_element from with all other
@@ -151,95 +128,6 @@ class CollectionElement:
         return self.deleted
 
 
-class Collection:
-    """
-    Represents all elements of one collection.
-    """
-
-    def __init__(self, collection_string: str, full_data: List[Dict[str, Any]] = None) -> None:
-        """
-        Initiates a Collection. A collection_string has to be given. If
-        full_data (a list of dictionaries) is not given the method
-        get_full_data() exposes all data by iterating over all
-        CollectionElements.
-        """
-        self.collection_string = collection_string
-        self.full_data = full_data
-
-    def get_model(self) -> Type[Model]:
-        """
-        Returns the django model that is used for this collection.
-        """
-        return get_model_from_collection_string(self.collection_string)
-
-    def get_access_permissions(self) -> 'BaseAccessPermissions':
-        """
-        Returns the get_access_permissions object for the this collection.
-        """
-        return self.get_model().get_access_permissions()
-
-    def element_generator(self) -> Generator[CollectionElement, None, None]:
-        """
-        Generator that yields all collection_elements of this collection.
-        """
-        for full_data in self.get_full_data():
-            yield CollectionElement.from_values(
-                self.collection_string,
-                full_data['id'],
-                full_data=full_data)
-
-    def get_elements_from_db(self) ->Dict[str, List[Dict[str, Any]]]:
-        # Hack for django 2.0 and channels 2.1 to stay in the same thread.
-        # This is needed for the tests.
-        try:
-            query = self.get_model().objects.get_full_queryset()
-        except AttributeError:
-            # If the model des not have to method get_full_queryset(), then use
-            # the default queryset from django.
-            query = self.get_model().objects
-        return {self.collection_string: [self.get_model().get_access_permissions().get_full_data(instance) for instance in query.all()]}
-
-    def get_full_data(self) -> List[Dict[str, Any]]:
-        """
-        Returns a list of dictionaries with full_data of all collection
-        elements.
-        """
-        if self.full_data is None:
-            # The type of all_full_data has to be set for mypy
-            all_full_data: Dict[str, List[Dict[str, Any]]] = {}
-            all_full_data = async_to_sync(element_cache.get_all_full_data)()
-            self.full_data = all_full_data.get(self.collection_string, [])
-        return self.full_data  # type: ignore
-
-    def as_list_for_user(self, user: Optional[CollectionElement]) -> List[Dict[str, Any]]:
-        """
-        Returns a list of dictonaries to send them to a user, for example over
-        the rest api.
-        """
-        return self.get_access_permissions().get_restricted_data(self.get_full_data(), user)
-
-    def get_collection_string(self) -> str:
-        """
-        Returns the collection_string.
-        """
-        return self.collection_string
-
-    def get_elements(self) -> List[Dict[str, Any]]:
-        """
-        Returns all elements of the Collection as full_data.
-        """
-        return self.get_full_data()
-
-    def restrict_elements(
-            self,
-            user: Optional['CollectionElement'],
-            elements: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
-        """
-        Converts the full_data to restricted data.
-        """
-        return self.get_model().get_access_permissions().get_restricted_data(user, elements)
-
-
 _models_to_collection_string: Dict[str, Type[Model]] = {}
 
 
@@ -268,5 +156,5 @@ def get_model_from_collection_string(collection_string: str) -> Type[Model]:
     try:
         model = _models_to_collection_string[collection_string]
     except KeyError:
-        raise ValueError('Invalid message. A valid collection_string is missing.')
+        raise ValueError('Invalid message. A valid collection_string is missing. Got {}'.format(collection_string))
     return model
diff --git a/openslides/utils/consumers.py b/openslides/utils/consumers.py
index 3a7d06aa2..f392e82f3 100644
--- a/openslides/utils/consumers.py
+++ b/openslides/utils/consumers.py
@@ -23,8 +23,12 @@ class SiteConsumer(ProtocollAsyncJsonWebsocketConsumer):
 
         Sends the startup data to the user.
         """
+        # If the user is the anonymous user, change the value to None
+        if self.scope['user'].id is None:
+            self.scope['user'] = None
+
         change_id = None
-        if not await async_anonymous_is_enabled() and self.scope['user'].id is None:
+        if not await async_anonymous_is_enabled() and self.scope['user'] is None:
             await self.close()
             return
 
@@ -61,7 +65,7 @@ class SiteConsumer(ProtocollAsyncJsonWebsocketConsumer):
         """
         Send a notify message to the user.
         """
-        user_id = self.scope['user'].id or 0
+        user_id = self.scope['user'].id if self.scope['user'] else 0
 
         out = []
         for item in event['incomming']:
diff --git a/openslides/utils/models.py b/openslides/utils/models.py
index f37b95b74..74389a5b3 100644
--- a/openslides/utils/models.py
+++ b/openslides/utils/models.py
@@ -134,11 +134,11 @@ class RESTModelMixin:
         return [cls.get_access_permissions().get_full_data(instance) for instance in query.all()]
 
     @classmethod
-    def restrict_elements(
+    async def restrict_elements(
             cls,
             user: Optional['CollectionElement'],
             elements: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
         """
         Converts a list of elements from full_data to restricted_data.
         """
-        return cls.get_access_permissions().get_restricted_data(elements, user)
+        return await cls.get_access_permissions().get_restricted_data(elements, user)
diff --git a/openslides/utils/redis.py b/openslides/utils/redis.py
new file mode 100644
index 000000000..86baaa86f
--- /dev/null
+++ b/openslides/utils/redis.py
@@ -0,0 +1,37 @@
+from typing import Any
+
+from django.conf import settings
+
+
+try:
+    import aioredis
+except ImportError:
+    use_redis = False
+else:
+    # set use_redis to true, if there is a value for REDIS_ADDRESS in the settings
+    redis_address = getattr(settings, 'REDIS_ADDRESS', '')
+    use_redis = bool(redis_address)
+
+
+class RedisConnectionContextManager:
+    """
+    Async context manager for connections
+    """
+    # TODO: contextlib.asynccontextmanager can be used in python 3.7
+
+    def __init__(self, redis_address: str) -> None:
+        self.redis_address = redis_address
+
+    async def __aenter__(self) -> 'aioredis.RedisConnection':
+        self.conn = await aioredis.create_redis(self.redis_address)
+        return self.conn
+
+    async def __aexit__(self, exc_type: Any, exc: Any, tb: Any) -> None:
+        self.conn.close()
+
+
+def get_connection() -> RedisConnectionContextManager:
+    """
+    Returns contextmanager for a redis connection.
+    """
+    return RedisConnectionContextManager(redis_address)
diff --git a/openslides/utils/rest_api.py b/openslides/utils/rest_api.py
index 36a9f3b72..cbd1578e8 100644
--- a/openslides/utils/rest_api.py
+++ b/openslides/utils/rest_api.py
@@ -1,6 +1,7 @@
 from collections import OrderedDict
 from typing import Any, Dict, Iterable, Optional, Type
 
+from asgiref.sync import async_to_sync
 from django.http import Http404
 from rest_framework import status
 from rest_framework.decorators import detail_route, list_route
@@ -42,7 +43,7 @@ from rest_framework.viewsets import (
 
 from .access_permissions import BaseAccessPermissions
 from .auth import user_to_collection_user
-from .collection import Collection, CollectionElement
+from .cache import element_cache
 
 
 __all__ = ['detail_route', 'DecimalField', 'list_route', 'SimpleMetadata',
@@ -187,11 +188,6 @@ class ModelSerializer(_ModelSerializer):
 class ListModelMixin(_ListModelMixin):
     """
     Mixin to add the caching system to list requests.
-
-    It is not allowed to use the method get_queryset() in derivated classes.
-    The attribute queryset has to be used in the following form:
-
-    queryset = Model.objects.all()
     """
     def list(self, request: Any, *args: Any, **kwargs: Any) -> Response:
         model = self.get_queryset().model
@@ -201,20 +197,14 @@ class ListModelMixin(_ListModelMixin):
             # The corresponding queryset does not support caching.
             response = super().list(request, *args, **kwargs)
         else:
-            collection = Collection(collection_string)
-            user = user_to_collection_user(request.user)
-            response = Response(collection.as_list_for_user(user))
+            all_restricted_data = async_to_sync(element_cache.get_all_restricted_data)(user_to_collection_user(request.user))
+            response = Response(all_restricted_data.get(collection_string, []))
         return response
 
 
 class RetrieveModelMixin(_RetrieveModelMixin):
     """
     Mixin to add the caching system to retrieve requests.
-
-    It is not allowed to use the method get_queryset() in derivated classes.
-    The attribute queryset has to be used in the following form:
-
-    queryset = Model.objects.all()
     """
     def retrieve(self, request: Any, *args: Any, **kwargs: Any) -> Response:
         model = self.get_queryset().model
@@ -225,15 +215,10 @@ class RetrieveModelMixin(_RetrieveModelMixin):
             response = super().retrieve(request, *args, **kwargs)
         else:
             lookup_url_kwarg = self.lookup_url_kwarg or self.lookup_field
-            collection_element = CollectionElement.from_values(
-                collection_string, self.kwargs[lookup_url_kwarg])
             user = user_to_collection_user(request.user)
-            try:
-                content = collection_element.as_dict_for_user(user)
-            except collection_element.get_model().DoesNotExist:
-                raise Http404
+            content = async_to_sync(element_cache.get_element_restricted_data)(user, collection_string, self.kwargs[lookup_url_kwarg])
             if content is None:
-                self.permission_denied(request)
+                raise Http404
             response = Response(content)
         return response
 
diff --git a/tests/conftest.py b/tests/conftest.py
index cc7364fc2..3bb7d4d21 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -1,4 +1,5 @@
 import pytest
+from asgiref.sync import async_to_sync
 from django.test import TestCase, TransactionTestCase
 from pytest_django.django_compat import is_django_unittest
 from pytest_django.plugin import validate_django_db
@@ -68,4 +69,5 @@ def reset_cache(request):
     """
     if 'django_db' in request.node.keywords or is_django_unittest(request):
         # When the db is created, use the original cachables
+        async_to_sync(element_cache.cache_provider.clear_cache)()
         element_cache.ensure_cache(reset=True)
diff --git a/tests/integration/agenda/test_viewset.py b/tests/integration/agenda/test_viewset.py
index ec7232d60..c1aa10067 100644
--- a/tests/integration/agenda/test_viewset.py
+++ b/tests/integration/agenda/test_viewset.py
@@ -42,7 +42,7 @@ class RetrieveItem(TestCase):
 
     def test_hidden_by_anonymous_without_manage_perms(self):
         response = self.client.get(reverse('item-detail', args=[self.item.pk]))
-        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+        self.assertEqual(response.status_code, 404)
 
     def test_hidden_by_anonymous_with_manage_perms(self):
         group = Group.objects.get(pk=1)  # Group with pk 1 is for anonymous users.
diff --git a/tests/integration/helpers.py b/tests/integration/helpers.py
index 439decd29..38b6c9f46 100644
--- a/tests/integration/helpers.py
+++ b/tests/integration/helpers.py
@@ -27,7 +27,7 @@ class TConfig:
             config.key_to_id[item.name] = id+1
         return elements
 
-    def restrict_elements(
+    async def restrict_elements(
             self,
             user: Optional['CollectionElement'],
             elements: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
@@ -50,7 +50,7 @@ class TUser:
              'last_email_send': None, 'comment': '', 'is_active': True, 'default_password': 'admin',
              'session_auth_hash': '362d4f2de1463293cb3aaba7727c967c35de43ee'}]
 
-    def restrict_elements(
+    async def restrict_elements(
             self,
             user: Optional['CollectionElement'],
             elements: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
diff --git a/tests/integration/motions/test_viewset.py b/tests/integration/motions/test_viewset.py
index 143bc67b7..9865e8f3d 100644
--- a/tests/integration/motions/test_viewset.py
+++ b/tests/integration/motions/test_viewset.py
@@ -428,7 +428,7 @@ class RetrieveMotion(TestCase):
         inform_changed_data(self.motion)
 
         response = guest_client.get(reverse('motion-detail', args=[self.motion.pk]))
-        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+        self.assertEqual(response.status_code, 404)
 
     def test_admin_state_with_required_permission_to_see(self):
         state = self.motion.state
@@ -461,6 +461,7 @@ class RetrieveMotion(TestCase):
         config['general_system_enable_anonymous'] = True
         guest_client = APIClient()
         inform_changed_data(group)
+        inform_changed_data(self.motion)
 
         response_1 = guest_client.get(reverse('motion-detail', args=[self.motion.pk]))
         self.assertEqual(response_1.status_code, status.HTTP_200_OK)
@@ -473,7 +474,7 @@ class RetrieveMotion(TestCase):
             password='password_ooth7taechai5Oocieya')
 
         response_3 = guest_client.get(reverse('user-detail', args=[extra_user.pk]))
-        self.assertEqual(response_3.status_code, status.HTTP_403_FORBIDDEN)
+        self.assertEqual(response_3.status_code, 404)
 
 
 class UpdateMotion(TestCase):
@@ -983,6 +984,7 @@ class TestMotionCommentSection(TestCase):
         section.save()
 
         response = self.client.get(reverse('motioncommentsection-list'))
+
         self.assertEqual(response.status_code, status.HTTP_200_OK)
         self.assertTrue(isinstance(response.data, list))
         self.assertEqual(len(response.data), 1)
@@ -995,10 +997,12 @@ class TestMotionCommentSection(TestCase):
         """
         self.admin.groups.remove(self.group_in)  # group_in has motions.can_manage permission
         self.admin.groups.add(self.group_out)  # group_out does not.
+        inform_changed_data(self.admin)
 
         section = MotionCommentSection(name='test_name_f3mMD28LMcm29Coelwcm')
         section.save()
         section.read_groups.add(self.group_out, self.group_in)
+        inform_changed_data(section)
 
         response = self.client.get(reverse('motioncommentsection-list'))
         self.assertEqual(response.status_code, status.HTTP_200_OK)
diff --git a/tests/integration/users/test_viewset.py b/tests/integration/users/test_viewset.py
index 6eb270465..994c0b34a 100644
--- a/tests/integration/users/test_viewset.py
+++ b/tests/integration/users/test_viewset.py
@@ -69,7 +69,7 @@ class UserGetTest(TestCase):
 
         response = guest_client.get('/rest/users/user/1/')
 
-        self.assertEqual(response.status_code, 403)
+        self.assertEqual(response.status_code, 404)
 
 
 class UserCreate(TestCase):
@@ -535,7 +535,7 @@ class PersonalNoteTest(TestCase):
         config['general_system_enable_anonymous'] = True
         guest_client = APIClient()
         response = guest_client.get(reverse('personalnote-detail', args=[personal_note.pk]))
-        self.assertEqual(response.status_code, status.HTTP_403_FORBIDDEN)
+        self.assertEqual(response.status_code, 404)
 
     def test_admin_send_JSON(self):
         admin_client = APIClient()
diff --git a/tests/integration/utils/test_collection.py b/tests/integration/utils/test_collection.py
index 873d43fc8..d2c7f8d2f 100644
--- a/tests/integration/utils/test_collection.py
+++ b/tests/integration/utils/test_collection.py
@@ -26,37 +26,3 @@ class TestCollectionElementCache(TestCase):
         """
         with self.assertRaises(Topic.DoesNotExist):
             collection.CollectionElement.from_values('topics/topic', 999)
-
-
-class TestCollectionCache(TestCase):
-    def test_with_cache(self):
-        """
-        Tests that no db query is used when the list is received twice.
-        """
-        Topic.objects.create(title='test topic1')
-        Topic.objects.create(title='test topic2')
-        Topic.objects.create(title='test topic3')
-        topic_collection = collection.Collection('topics/topic')
-        list(topic_collection.get_full_data())
-
-        with self.assertNumQueries(0):
-            instance_list = list(topic_collection.get_full_data())
-        self.assertEqual(len(instance_list), 3)
-
-    def test_deletion(self):
-        """
-        When an element is deleted, the cache should be updated automaticly via
-        the autoupdate system. So there should be no db queries.
-        """
-        Topic.objects.create(title='test topic1')
-        Topic.objects.create(title='test topic2')
-        topic3 = Topic.objects.create(title='test topic3')
-        topic_collection = collection.Collection('topics/topic')
-        list(topic_collection.get_full_data())
-
-        collection.CollectionElement.from_instance(topic3, deleted=True)
-        topic3.delete()
-
-        with self.assertNumQueries(0):
-            instance_list = list(collection.Collection('topics/topic').get_full_data())
-        self.assertEqual(len(instance_list), 2)
diff --git a/tests/settings.py b/tests/settings.py
index 765edc90e..4338177a0 100644
--- a/tests/settings.py
+++ b/tests/settings.py
@@ -75,3 +75,6 @@ MOTION_IDENTIFIER_MIN_DIGITS = 1
 PASSWORD_HASHERS = [
     'django.contrib.auth.hashers.MD5PasswordHasher',
 ]
+
+# Deactivate restricted_data_cache
+RESTRICTED_DATA_CACHE = False
diff --git a/tests/unit/users/test_access_permissions.py b/tests/unit/users/test_access_permissions.py
deleted file mode 100644
index 1561c7a84..000000000
--- a/tests/unit/users/test_access_permissions.py
+++ /dev/null
@@ -1,20 +0,0 @@
-from unittest import TestCase
-
-from openslides.users.access_permissions import PersonalNoteAccessPermissions
-from openslides.utils.collection import CollectionElement
-
-
-class TestPersonalNoteAccessPermissions(TestCase):
-    def test_get_restricted_data(self):
-        ap = PersonalNoteAccessPermissions()
-        rd = ap.get_restricted_data(
-            [{'user_id': 1}],
-            CollectionElement.from_values('users/user', 5, full_data={}))
-        self.assertEqual(rd, [])
-
-    def test_get_restricted_data_for_anonymous(self):
-        ap = PersonalNoteAccessPermissions()
-        rd = ap.get_restricted_data(
-            [{'user_id': 1}],
-            None)
-        self.assertEqual(rd, [])
diff --git a/tests/unit/utils/cache_provider.py b/tests/unit/utils/cache_provider.py
index 4c0ead6fd..7e57e5767 100644
--- a/tests/unit/utils/cache_provider.py
+++ b/tests/unit/utils/cache_provider.py
@@ -32,7 +32,7 @@ class Collection1:
             {'id': 1, 'value': 'value1'},
             {'id': 2, 'value': 'value2'}]
 
-    def restrict_elements(self, user: Optional[CollectionElement], elements: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
+    async def restrict_elements(self, user: Optional[CollectionElement], elements: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
         return restrict_elements(user, elements)
 
 
@@ -45,7 +45,7 @@ class Collection2:
             {'id': 1, 'key': 'value1'},
             {'id': 2, 'key': 'value2'}]
 
-    def restrict_elements(self, user: Optional[CollectionElement], elements: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
+    async def restrict_elements(self, user: Optional[CollectionElement], elements: List[Dict[str, Any]]) -> List[Dict[str, Any]]:
         return restrict_elements(user, elements)
 
 
diff --git a/tests/unit/utils/test_cache.py b/tests/unit/utils/test_cache.py
index f90ac7623..43b505390 100644
--- a/tests/unit/utils/test_cache.py
+++ b/tests/unit/utils/test_cache.py
@@ -30,7 +30,6 @@ def sort_dict(encoded_dict: Dict[str, List[Dict[str, Any]]]) -> Dict[str, List[D
 @pytest.fixture
 def element_cache():
     element_cache = ElementCache(
-        'test_redis',
         cache_provider_class=TTestCacheProvider,
         cachable_provider=get_cachable_provider(),
         start_time=0)