The attacker can specify his own plain text and encrypt or sign it.
6
votes
2answers
479 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 ...
0
votes
2answers
133 views
CPA distinguisher for matrix multiplication in GF(256) with randomized padding
What is the best CPA distinguisher for the function $F_k:\{0,1\}^{8n}\to\{0,1\}^{16n}$ described below?
Let $E_k$ be a $2n\times2n$ matrix with elements in $GF(2^8)$, selected by generating bit ...