Keccak-256
Web3 / privacy technology
Keccak-256 is the cryptographic hash function used throughout the Ethereum protocol for generating addresses, hashing transaction data, and creating merkle trees. It was selected from the SHA-3 family of hash functions and produces a 256-bit output from any input data. While Ethereum uses Keccak-256 rather than the final NIST-standardized SHA-3, the underlying algorithm is nearly identical, providing robust security properties that prevent collision attacks and ensure that even tiny changes in input produce completely different outputs. This deterministic function is essential for Ethereum's ability to verify data integrity and create immutable records. Example: Ethereum account addresses are derived by taking the Keccak-256 hash of a public key and using the last 20 bytes of the result, demonstrating how the hash function enables the creation of secure, unique identifiers. Why it matters for privacy technology: Keccak-256's cryptographic properties ensure that sensitive data like private keys cannot be reverse-engineered from hashes, and the function's widespread adoption across Ethereum tooling makes it fundamental to the ecosystem's security architecture.
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