AES Algorithm: State Block Transformation with S-box (Illustrated Example)

The size of the State block is 4x4, meaning it contains 16 bytes of data.

To apply the AES S-box transformation, we first substitute each byte in the State block with a new value from the S-box table. The S-box table is a fixed 16x16 lookup table that maps each possible byte value to a new value.

Using the S-box table, we can transform the State block as follows:

D1 26 B9 3C -> 8E 4D A1 0B 59 C2 AC 42 -> 3A D7 F7 A7 15 BC 42 A9 -> 78 5F 7C 67 39 DA D3 26 -> 21 5E 9B 5A

The new State block after applying the AES S-box transformation is:

8E 3A 78 21 4D D7 5F 5E A1 F7 7C 9B 0B A7 67 5A

Each column in the new State block represents a 4-tuple of bytes that have been transformed using the AES S-box. The S-box transformation is a non-linear substitution that helps to increase the security of the AES algorithm by adding confusion to the data.