Could some one please help me figure this question out? I will rate! Thank you!!

2. Consider a block encryption algorithm that encrypts blocks of n, and let N=2". Say we have t plaintext- ciphertext pairs Pi,C; = E(K,P;), where we assume that the key K selects one of the N! possible mappings. Imagine that we wish to find K by exhaustive search. We could generate key K' and test whether (i = E(K',P;) for 1