SHA-3 Family Reference
Reference 为 SHA-3 (Keccak) hash 族: SHA3-224, SHA3-256, SHA3-384, SHA3-512, SHAKE128, SHAKE256.
Sponge Construction
SHA-3 is based on the Keccak sponge construction with a 1600-bit state and configurable rate/capacity. The permutation applies 24 rounds of five steps: theta, rho, pi, chi, iota. The capacity determines security: collision resistance is c/2 bits and preimage resistance is c bits. SHAKE128 and SHAKE256 are extendable-output functions (XOFs) producing arbitrary-length digests.
- state
- 1600-bit permutation
- rounds
- 24 rounds always
- capacity
- Determines security
Keccak-f[1600]5 steps eachc = 2x output sizeStandardization and Use
SHA-3 was standardized in FIPS 202 after winning the NIST hash competition in 2012. It provides a design completely independent from SHA-2, offering insurance against future SHA-2 breaks. SHAKE XOFs are used in post-quantum signatures (SPHINCS+, Dilithium) and as random oracle simulators in proofs. The parallelizable nature of sponge construction enables efficient tree hashing.
- FIPS 202
- NIST standard
- SHAKE
- Extendable output
- PQC use
- SPHINCS+, Dilithium
Keccak selectedXOFhash-based sigs