Hybrid Forward Secrecy
New modifiers and tokens for KEM-based hybrid forward secrecy.
An unofficial/unstable extension spec exists.
We want this to be consistent with an eventual "multi-algorithm" approaches that allows arbitrary mixing of KEMs, signatures, and DH. But we probably have a good enough idea of what token syntax for KEMs will look like that we can move ahead now with a simple modifier for this special case.
https://github.com/noiseprotocol/noise_hfs_spec/blob/master/output/noise_hfs.pdf https://github.com/noiseprotocol/noise_hfs_spec
None
https://moderncrypto.org/mail-archive/noise/2018/001874.html