SHA-224
SHA-224 is the 224-bit truncated variant of the SHA-2 family, using the same round function as SHA-256 but different initial hash values, outputting a 28-byte digest.
Purpose
Provides a collision-resistant hash where a 224-bit security level is needed, e.g. DSA 224-bit signatures and IPsec.
Mechanism
Algorithmically identical to SHA-256 (64 rounds, 32-bit words), but the initial value is taken from an intermediate SHA-256 value, and the output is truncated to the high 224 bits.
Use cases
- DSA-224 signatures
- IPsec ESP authentication
- Medium-security digests