diff --git a/CMakeLists.txt b/CMakeLists.txt
index a64be4d..f3e9b79 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -49,6 +49,18 @@ if(NOT expected_POPULATED)
   FetchContent_Populate(expected)
 endif(NOT expected_POPULATED)
 
+# add crypt++ (+cmake) library
+set(CRYPTOPP_BUILD_TESTING Off)
+set(CRYPTOPP_INSTALL Off)
+
+if(NOT cryptopp_POPULATED)
+  FetchContent_Declare(cryptopp
+    GIT_REPOSITORY https://github.com/abdes/cryptopp-cmake.git
+    GIT_TAG CRYPTOPP_8_7_0)
+  FetchContent_Populate(cryptopp)
+  add_subdirectory(${cryptopp_SOURCE_DIR} ${cryptopp_BINARY_DIR})
+endif(NOT cryptopp_POPULATED)
+
 include(CTest)
 enable_testing()
 
@@ -80,7 +92,7 @@ set(LIB_SOURCES
   src/big_int.hpp src/big_int.cpp )
 
 add_library(oc-mint-lib ${LIB_SOURCES})
-target_link_libraries(oc-mint-lib PUBLIC Crow::Crow)
+target_link_libraries(oc-mint-lib PUBLIC Crow::Crow cryptopp::cryptopp)
 target_include_directories(oc-mint-lib PUBLIC ${expected_SOURCE_DIR}/include src) 
 
 add_executable(${PROJECT_NAME} src/main.cpp)