HMAC

E37198
cryptographic construction keyed hash function message authentication code

HMAC (Hash-based Message Authentication Code) is a cryptographic construction that combines a secret key with a hash function to provide data integrity and authentication.

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Observed surface forms (5)

Surface form Occurrences
HMAC-MD5-96 2
HMAC-SHA-96 2
HMAC-SHA1 2

Statements (49)

Predicate Object
instanceOf cryptographic construction ⓘ
keyed hash function ⓘ
message authentication code ⓘ
advantage no need for new primitives beyond hash ⓘ
simple to implement ⓘ
widely supported in libraries ⓘ
canBeTruncated yes ⓘ
comparisonRequirement constant-time comparison recommended ⓘ
component inner hash computation ⓘ
outer hash computation ⓘ
constructionType hash-based MAC ⓘ
definedOver iterated hash functions ⓘ
designGoal black-box use of hash function ⓘ
provable security under standard assumptions ⓘ
fullName HMAC self-linksurface differs ⓘ
surface form: Hash-based Message Authentication Code
introducedBy Hugo Krawczyk ⓘ
Mihir Bellare ⓘ
Ran Canetti ⓘ
keyProcessing keys longer than block size are hashed ⓘ
keys shorter than block size are padded with zeros ⓘ
outputType authentication tag ⓘ
fixed-length tag ⓘ
property resistant to length extension attacks (when underlying hash is vulnerable) ⓘ
provides data integrity ⓘ
message authentication ⓘ
origin authentication ⓘ
recommendedKeyLength at least as long as hash output ⓘ
requires shared secret key ⓘ
securityDependsOn key secrecy ⓘ
secret key length ⓘ
underlying hash function ⓘ
standardizedIn FIPS 198-1 ⓘ
RFC 2104 ⓘ
typicalHashFunction MD5 ⓘ
SHA-1 ⓘ
SHA-256 ⓘ
SHA-512 ⓘ
usedFor API authentication ⓘ
IPsec ⓘ
JSON Web Tokens (JWT) ⓘ
SSH ⓘ
TLS ⓘ
message integrity checks ⓘ
uses cryptographic hash function ⓘ
secret key ⓘ
usesConstant inner padding (ipad) ⓘ
outer padding (opad) ⓘ
verificationMethod recompute and compare tag ⓘ
yearIntroduced 1996 ⓘ

Referenced by (11)

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

this entity surface form: HMAC-MD5-96
this entity surface form: HMAC-SHA-96
this entity surface form: HMAC-SHA1
Poly1305 → comparedTo → HMAC ⓘ
RFC 3546 → defines → HMAC ⓘ
this entity surface form: Truncated HMAC extension
HMAC → fullName → HMAC self-linksurface differs ⓘ
this entity surface form: Hash-based Message Authentication Code
RFC 4346 → supports → HMAC ⓘ
this entity surface form: HMAC-MD5-96
this entity surface form: HMAC-SHA-96
TLS 1.0 → supportsMAC → HMAC ⓘ
this entity surface form: HMAC-SHA1
RFC 5246 → uses → HMAC ⓘ