Q. Explain one round of cipher. You can assume that key expansion is done by a separate process. Don’t need to explain that. You can assume that your encryption function takes an array of N keys, where N is the number of rounds in your cipher.

Structure of cipher is similar to SPN.

Keylength=32 , Blocklength=32

Assuming Kr is the round key used in the round We divide the input into 8 blocks of 4 bits each,the following are done in 1 round of cipher

1.Substitution: 4x4 sbox is used here.

The operations in substitution are: …