AddRoundKey

E171108

AddRoundKey is a core AES transformation step that combines the current state with a round-specific subkey using bitwise XOR to provide key-dependent confusion.

All labels observed (1)

Label Occurrences
AddRoundKey canonical 2

How this entity was disambiguated

Statements (46)

Predicate Object
instanceOf AES transformation step
cryptographic primitive operation
actsOn each state byte with corresponding key byte
appliedBitwise via XOR on bits of state and key
appliedBytewise true
appliesTo AES state
category symmetric-key cryptography operation
commutesWith other XOR-based key additions on same state
complexity linear time in state size
definedBy Advanced Encryption Standard
surface form: FIPS 197
doesNotChange state size
implementation bitwise XOR gates in hardware
bytewise XOR instructions in software
input current AES state
round key
introducedWith Rijndael
surface form: Rijndael cipher
inverseOperation AddRoundKey
isKeyDependent true
isLinearOver GF(2)
mathematicalDescription state = state XOR roundKey
operatesOn 128-bit state
4x4 byte matrix
state matrix
output updated AES state
partOf AES round function
Advanced Encryption Standard
performedIn every AES decryption round
every AES encryption round
positionInRound first step of AES encryption round
last step of AES decryption round
provides key-dependent confusion
requires expanded key schedule
reversibility self-inverse operation
roundDependency round index determines subkey
securityRole binds encryption to secret key
prevents keyless recovery of plaintext
standardizedIn Advanced Encryption Standard
surface form: AES specification
usedFor both encryption and decryption in AES
usedIn Advanced Encryption Standard
surface form: AES-128

Advanced Encryption Standard
surface form: AES-192

Advanced Encryption Standard
surface form: AES-256
usedWith MixColumns
ShiftRows
SubBytes
uses round subkey
usesOperation bitwise XOR

How these facts were elicited

Referenced by (2)

Full triples — surface form annotated when it differs from this entity's canonical label.

MixColumns precedes AddRoundKey