Editing Advanced Encryption Standard (section)

=== The {{mono|AddRoundKey}}  ===
[[Image:AES-AddRoundKey.svg|right|320px|thumbnail|In the {{mono | AddRoundKey}} step, each byte of the state is combined with a byte of the round subkey using the [[Exclusive or|XOR]] operation (⊕).]]
In the {{mono | AddRoundKey}} step, the subkey is combined with the state. For each round, a subkey is derived from the main [[key (cryptography)|key]] using [[Rijndael key schedule|Rijndael's key schedule]]; each subkey is the same size as the state. The subkey is added by combining of the state with the corresponding byte of the subkey using bitwise [[Exclusive or|XOR]].