SHA3like

SHA3like is a descriptive term used in cryptography to refer to hash-functions or hash-function families that resemble the SHA-3 design, either in construction, interface, or both. It is not an official standard; there is no single specification for SHA3like. In practice, SHA3like schemes are based on the sponge construction or Keccak-inspired primitives and aim to provide similar security properties and API potential as SHA-3 variants, but with their own parameter choices and padding rules.

Core characteristics commonly found in SHA3like designs include absorbing the input into a fixed-size state in blocks of a rate r, applying a permutation to the state, and squeezing output bits to produce the hash. The total state size b equals r plus the capacity c. The capacity typically governs security against preimage and collision attacks, with c approximately twice the desired security level. Many SHA3like schemes reuse the padding convention from SHA-3 (multi-rate padding), but some variants modify padding, domain separation, or the output length.

SHA3like functions may expose an API akin to SHA3 or SHAKE, either producing fixed-length digests or extendable outputs. While they share goals with SHA-3, their security proofs, parameter choices, and real-world deployments vary and are not standardized. They appear mainly in research, experimental implementations, or protocol-specific components.

In summary, SHA3like denotes a broad class of sponge- or Keccak-based hash ideas that resemble SHA-3 in spirit without being official SHA-3 standards.