Keccak-256

A Keccak hash function with a 256-bit output, used extensively in Ethereum.

PLAIN-ENGLISH DEFINITION

In more detail

Ethereum uses Keccak-256 for many identifiers and commitments. It is related to SHA-3, but Ethereum's variant and standardized SHA3-256 use different padding conventions and produce different digests. This matters when a developer reproduces a function selector or checks data against an Ethereum-generated value.

IN THE WILD

How you might use it

"My function selector doesn't match." The tool used SHA3-256, while the Ethereum contract expects its Keccak-256 variant.

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By Crypto Dictionary · Published Oct 9, 2026 · Updated Oct 10, 2026

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