SHA-224

IDsha22404 / 38SHA · 224-bit

Hash / Cryptographic

SHA-224

SHA-256 with other start values, cut to 28 bytes.

Digest: 224-bit · 28 bytes
HMAC: takes a key
Security: 112-bit collision resistance
Family: 12 in SHA

4 options, 0 required

Sample

hex: 2f05477fc24bb4faefd86517156dafdecec45b8ad3cf2522a563582b
base64: LwVHf8JLtPrv2GUXFW2v3s7EW4rTzyUipWNYKw==

Options

encodingstring: default hex; Output encoding: hex, base64, base64url, binary
keystring: optional; HMAC key; enables HMAC mode
roundsnumber: default 1; How many times to hash, each round hashing the previous digest
chainstring: default bytes; What each round after the first hashes: bytes of the digest, or its lowercase hex

Access

Createcreate("sha224")

CLIhashes sha224 'hello world'

Tryplayground with the sample above

Kinsha256, sha384, sha512, sha512-224 +7

SHA-256 on a diet. Same rounds, same constants, other initial values, and the digest stops at 28 bytes. NIST added it in 2004 to match 112-bit security, the level of P-224 and three-key Triple DES.

So is it the first 28 bytes of SHA-256? No. SHA-256 of abc starts with ba7816bf, this one with 23097d22. The start values change every byte.

It costs exactly as much as SHA-256 and gives you less. That's fine when a spec asks for it, and odd anywhere else. Want 28 bytes on a 64-bit machine? SHA-512/224 gets there faster.