SHA-256
Cryptography● Common
A cryptographic hash function producing a 256-bit (32-byte) output. Bitcoin uses double-SHA256 (SHA256d) for block headers, transaction IDs, and merkle trees. Mining is essentially a SHA256d lottery to find hashes below target.
Technical Notes
SHA-256 designed by NSA, part of SHA-2 family. Properties: deterministic, fast, preimage-resistant, collision-resistant, avalanche effect. Double-SHA256 prevents length extension attacks. ASIC miners compute ~100+ TH/s of SHA256d operations.
Metadata
Visibility: Public
Created:1/3/2026by System