Question

What is the maximum number of different encryption functions of a block cipher over the alphabet {0,1} with block length n?

Answer 1

Here is your answer...

Here given block length=n;

Key size =2 bit

Encryption function is like.

$E_K(P) := E(K,P): \{0,1\}^k \times \{0,1\}^n \rightarrow \{0,1\}^n,$

So, Maximum number of different encryption function of block cipher would be (factorial of 2ⁿ) = (2ⁿ ) !