Editing Advanced Encryption Standard (section)

=== High-level description of the algorithm ===

# {{mono | KeyExpansion}}{{snd}}round keys are derived from the cipher key using the [[AES key schedule]]. AES requires a separate 128-bit round key block for each round plus one more.
# Initial round key addition:
## {{mono | AddRoundKey}}{{snd}}each byte of the state is combined with a byte of the round key using [[bitwise xor]].
# 9, 11 or 13 rounds:
## {{mono | SubBytes}}{{snd}}a [[linear map|non-linear]] substitution step where each byte is replaced with another according to a [[Rijndael S-box|lookup table]].
## {{mono | ShiftRows}}{{snd}}a transposition step where the last three rows of the state are shifted cyclically a certain number of steps.
## {{mono | MixColumns}}{{snd}}a linear mixing operation which operates on the columns of the state, combining the four bytes in each column.
## {{mono | AddRoundKey}}
# Final round (making 10, 12 or 14 rounds in total):
## {{mono | SubBytes}}
## {{mono | ShiftRows}}
## {{mono | AddRoundKey}}