Hey Piotr, Thanks a lot for the python test vector. It's been added to the repo as: https://git.zx2c4.com/WireGuard/commit/?id=09bf49bbddeb86f88654bb39e64268420b8fc5e4 And here's a video of it in action: https://data.zx2c4.com/wireguard-python-test-vector-works.ogv Regards, Jason