SHA-3
What is SHA-3?
SHA-3A family of hash functions based on the Keccak sponge construction, standardized by NIST as a structurally different alternative to SHA-2.
SHA-3 is the NIST hash standard published in FIPS 202 (2015), based on the Keccak algorithm selected after a 2007–2012 public competition. Unlike SHA-2, it uses a sponge construction with a 1600-bit permutation, which absorbs the message and then squeezes out the digest, providing robustness against length-extension attacks. The family defines SHA3-224, SHA3-256, SHA3-384 and SHA3-512 plus the extendable-output functions SHAKE128 and SHAKE256. SHA-3 has no known practical weaknesses and is recommended where domain separation from SHA-2 is desirable or where extendable output is needed (e.g., KMAC, post-quantum signature schemes).
● Examples
- 01
Ethereum uses Keccak-256 (a SHA-3 variant) for addresses and Merkle trees.
- 02
SHAKE128 is used as the extendable-output function in CRYSTALS-Dilithium.
● Frequently asked questions
What is SHA-3?
A family of hash functions based on the Keccak sponge construction, standardized by NIST as a structurally different alternative to SHA-2. It belongs to the Cryptography category of cybersecurity.
What does SHA-3 mean?
A family of hash functions based on the Keccak sponge construction, standardized by NIST as a structurally different alternative to SHA-2.
How do you defend against SHA-3?
Defences for SHA-3 typically combine technical controls and operational practices, as detailed in the full definition above.
What are other names for SHA-3?
Common alternative names include: Keccak, FIPS 202.