Message 273360 - Python tracker

In this case, performance is security. Both AES-GCM and ChaCha20-Poly1305 are secure. Modulo one thing: GCM in software is hard to implement in constant-time, so it's strongly preferable to use it only when there's a hardware implementation. It works out nicely that in addition to being constant-time, the hardware implementation of GCM is faster.