224bit

224bit refers to something described by a length of 224 binary digits. In cryptography and computing, this unit is often used to describe the size of a value such as a hash output, a large random identifier, or, less commonly, a key length. The most prominent association of 224 bits is with the SHA-224 hashing algorithm.

SHA-224 is part of the SHA-2 family and produces a 224-bit digest. It shares the same internal compression function as SHA-256 but uses different initial hash values and truncates the final hash to 224 bits. Because of its shorter output, SHA-224 provides a different security profile than SHA-256: preimage resistance is effectively on the order of 2^224, while collision resistance is about 2^112, compared with about 2^128 for SHA-256’s collision resistance.

In practice, 224-bit digests are used for data integrity checks, digital signatures, and other applications where a fixed-size hash is required. They are defined in standards such as FIPS 180-4 and are implemented in many cryptographic libraries. Over time, the cryptographic community has generally recommended longer digests (for example, 256 or more bits) to maintain margin against advances in attack techniques, so SHA-224 is less commonly chosen for new designs when higher security margins are desired. Some legacy systems and standards still specify or permit SHA-224 for compatibility reasons.

Beyond hash outputs, 224-bit length can describe large binary numbers or identifiers, but in cryptography it most often appears in discussions of the SHA-224 digest and related data integrity or signature workflows. The number 2^224 represents the size of the value space for a 224-bit quantity, roughly 2.7 × 10^67 possibilities.