The cipher suite is part of the Noise preamble, so all operations are crytographically bound to the cipher suite to prevent against related-algo attacks. WireGu

The cipher suite is part of the Noise preamble, so all operations are crytographically bound to the cipher suite to prevent against related-algo attacks. WireGuard itself has no plans for cipher agility, something that is considered an anti-feature. If these ciphers are ever considered problematic, we'll change them and release a new version (with an incremented preamble), and the new set of ciphers will be similarly non-configurable. Fortunately AVX2-accelerated (and soon AVX512-accelerated) ChaPoly is super fast in pretty much all hardware.