Iterating block ciphers Iterated block cipher Random( binary)keyK→ round keys:K1…,KN 2. Round function g W=g w-1, kr), where wr-1 is the previous state4 Iterating Block ciphers 1. Iterated block cipher Random (binary) key K ➔ round keys: K1 ,..., K Nr , 2. Round function g wr = g(wr-1 , Kr ), where wr-1 is the previous state