Crypto Hash Functions Explained: From SHA-256 to Keccak and…
By Damilola Esebame
AI summary of the source article
Major blockchains rely on differing cryptographic hash functions, including Bitcoin's double SHA-256, Ethereum's Keccak-256, and Litecoin's memory-intensive Scrypt. Ethereum uses original Keccak because it adopted the algorithm before NIST finalised the modified SHA-3 standard in 2015.
Why it matters
Each decision carries consequences for network security, hardware economics, and long-term quantum resistance.
Key facts
- Ethereum adopted the original Keccak submission before NIST finalised its modified SHA-3 standard in August 2015, making the two outputs different.
- Bitcoin applies SHA-256 twice in sequence, and no working collision or preimage attack has been found on full SHA-256 as of October 2026.
- BIP-360 was merged as a draft into the BIP repository in February 2026 to propose a quantum-resistant Bitcoin address design.
Source excerpt · FinanceFeeds
KEY TAKEAWAYS SHA-256 produces a fixed 256-bit output from an input of any size, and Bitcoin applies it twice to block data. Ethereum chose Keccak-256 over standard SHA-3 because Ethereum adopted the original Keccak submission before NIST finalised its modified SHA-3 standard, so the two algorithms produce different outputs. Litecoin adopted Scrypt to make mining more memory-intensive and discoura…