[cm3]

Thanks, and yes, I've read about what hardness assumption is used.

My confusion is about what pieces are concatenated. Is the same input processed twice (different ciphers) and then concatenated, which is then the generated key?

[tptacek]

The outputs of an RLWE and ECDH handshake are both fed into the TLS KDF.

[cm3]

Thanks for the info. May I ask if you figured that out from the blog or BoringSSL code?

[pbsd]

The hybrid ciphersuite idea comes from [1, Section 5.2], though you could also chalk it up to common sense. I don't think the blog spells out how it's done.

[1] https://eprint.iacr.org/2014/599

[wolf550e]

Adam Langley answered this on HN: https://news.ycombinator.com/item?id=12051438