diff --git a/.gitmodules b/.gitmodules
index 3d415661de..b019469bf9 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -67,3 +67,6 @@
 	path = src/drivers/uavcan_v1/legacy_data_types
 	url = https://github.com/PX4/public_regulated_data_types.git
 	branch = legacy
+[submodule "src/lib/crypto/monocypher"]
+	path = src/lib/crypto/monocypher
+	url = https://github.com/PX4/Monocypher.git
diff --git a/Tools/astyle/files_to_check_code_style.sh b/Tools/astyle/files_to_check_code_style.sh
index ba3557aea0..3eec9a2855 100755
--- a/Tools/astyle/files_to_check_code_style.sh
+++ b/Tools/astyle/files_to_check_code_style.sh
@@ -22,4 +22,5 @@ exec find boards msg src platforms test \
     -path src/modules/micrortps_bridge/micro-CDR -prune -o \
     -path src/modules/micrortps_bridge/microRTPS_client -prune -o \
     -path test/mavsdk_tests/catch2 -prune -o \
+    -path src/lib/crypto/monocypher -prune -o \
     -type f \( -name "*.c" -o -name "*.h" -o -name "*.cpp" -o -name "*.hpp" \) | grep $PATTERN
diff --git a/src/lib/CMakeLists.txt b/src/lib/CMakeLists.txt
index 56f4907fa3..e0c838a873 100644
--- a/src/lib/CMakeLists.txt
+++ b/src/lib/CMakeLists.txt
@@ -33,6 +33,7 @@
 
 px4_add_git_submodule(TARGET git_ecl PATH "ecl")
 px4_add_git_submodule(TARGET git_matrix PATH "matrix")
+px4_add_git_submodule(TARGET git_monocypher PATH "crypto/monocypher")
 
 add_subdirectory(airspeed)
 add_subdirectory(airspeed_validator)
@@ -45,6 +46,7 @@ add_subdirectory(collision_prevention)
 add_subdirectory(controllib)
 add_subdirectory(component_information)
 add_subdirectory(conversion)
+add_subdirectory(crypto)
 add_subdirectory(drivers)
 add_subdirectory(ecl)
 add_subdirectory(hysteresis)
diff --git a/src/lib/crypto/CMakeLists.txt b/src/lib/crypto/CMakeLists.txt
new file mode 100644
index 0000000000..05b6b413b9
--- /dev/null
+++ b/src/lib/crypto/CMakeLists.txt
@@ -0,0 +1,45 @@
+############################################################################
+#
+#   Copyright (c) 2021 Technology Innoavation Institute. All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions
+# are met:
+#
+# 1. Redistributions of source code must retain the above copyright
+#    notice, this list of conditions and the following disclaimer.
+# 2. Redistributions in binary form must reproduce the above copyright
+#    notice, this list of conditions and the following disclaimer in
+#    the documentation and/or other materials provided with the
+#    distribution.
+# 3. Neither the name PX4 nor the names of its contributors may be
+#    used to endorse or promote products derived from this software
+#    without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+# "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+# LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
+# FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
+# COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
+# INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
+# BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
+# OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
+# AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+# LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
+# ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
+# POSSIBILITY OF SUCH DAMAGE.
+#
+############################################################################
+
+px4_add_library(monocypher
+	monocypher/src/monocypher.c
+	monocypher/src/optional/monocypher-ed25519.c
+)
+
+target_include_directories(monocypher
+	PUBLIC
+		${CMAKE_CURRENT_SOURCE_DIR}/monocypher/src
+)
+
+# There is a one shadow warning in monocypher 3.1.2, ignore it
+target_compile_options(monocypher PRIVATE -Wno-shadow)
diff --git a/src/lib/crypto/monocypher b/src/lib/crypto/monocypher
new file mode 160000
index 0000000000..baca5d3125
--- /dev/null
+++ b/src/lib/crypto/monocypher
@@ -0,0 +1 @@
+Subproject commit baca5d31259c598540e4d1284bc8d8f793abf83a