Inside an AES Encryption Round
Trace the 128-bit state as it moves through one round of the Advanced Encryption Standard.
AES transforms a 4×4 byte matrix through a sequence of invertible steps. Each round mixes substitution, permutation, and linear algebra to diffuse every input bit across the entire block. Follow the interactive timeline below to observe how the state and round key evolve as we progress through a typical middle round.
Round Key Slice
Keys are expanded into 44 words for AES-128. Each round consumes four words (16 bytes) produced by the Rijndael key schedule. Notice how rotations, S-box lookups, and round constants reshape the key material every cycle.