SHA224 Hash Generator

What is SHA-224?

SHA-224 is the shortest member of the SHA-2 family standardized in NIST FIPS 180-4. It always produces 224 bits, which is 28 bytes or 56 hexadecimal characters, whatever the size of the input.

How to use the SHA-224 generator

Data

Type text or upload files. Text can be up to 100 MiB, read as UTF-8, and each file up to 2 GiB. Every input is hashed on its own.

Output

One digest per input, as raw bytes (digest) and as lowercase hexadecimal (hex).

Why use SHA-224 instead of SHA-256

It is SHA-256's machinery with a different starting state and a shorter result. The compression function, block size and word size are all shared, so it costs the same to compute as SHA-256 while returning four fewer bytes.

That is only worth having when something else fixes the size for you: a protocol field, a legacy record layout, or a matching 112-bit security target. When nothing constrains the length, the extra four bytes of SHA-256 are free and more widely supported.

SHA-224 alternatives

SHA-256 is the default choice and the one other systems expect. The SHA512 Hash Generator offers SHA-512/224, which lands on the same digest size through a different route and runs faster on 64-bit hardware.

Those two are not interchangeable with this one. SHA-224 and SHA-512/224 produce different digests for the same input despite the matching length, so match whichever the other system specifies.

Things to know about SHA-224

Because the output is a truncation of a larger internal state, SHA-224 does not give an attacker enough for the length-extension trick that works against full SHA-256. That is a side effect of the shorter output rather than a design goal.

Like any hash it runs one way only, and the input cannot be recovered from the digest. Fifty-six hexadecimal characters is an unusual length and a useful clue: find one in a log and SHA-224 and SHA-512/224 are your two candidates.