Rusty Russell [ARCHIVE] on Nostr: 📅 Original date posted:2016-06-27 📝 Original message:To quote: > ...

📅 Original date posted:2016-06-27
📝 Original message:To quote:

> HMAC_SHA512(key=ecdh_secret|cipher-type,msg="encryption key").
>
> K_1 must be the left 32bytes of the HMAC_SHA512 hash.
> K_2 must be the right 32bytes of the HMAC_SHA512 hash.

This seems a weak reason to introduce SHA512 to the mix. Can we just
make:

K_1 = HMAC_SHA256(key=ecdh_secret|cipher-type,msg="header encryption key")
K_2 = HMAC_SHA256(key=ecdh_secret|cipher-type,msg="body encryption key")

Thanks,
Rusty.