Cipher Feedback Mode (CFB) is an encryption mode, that builds a self-synchronizing stream-cipher from a block-cipher.

learn more… | top users | synonyms

10
votes
2answers
1k views

Is using a predictable IV with CFB mode safe or not?

While writing this answer, I noted that NIST SP 800-38A says that (emphasis mine): "For the CBC and CFB modes, the IVs must be unpredictable. In particular, for any given plaintext, it must not be ...