SHA-256 (Secure Hash Algorithm 256-bit)

Definition

SHA-256 is part of the SHA-2 family designed by the NSA and published by NIST in FIPS 180-4. It produces a 256-bit digest from any input data. SHA-256 is widely used for: TLS/SSL certificates, blockchain (Bitcoin uses SHA-256 for proof-of-work), password hashing (with salting), digital signatures, and file integrity verification. It is considered secure against known cryptographic attacks as of 2026. SHA-256 processes data in 512-bit blocks and performs 64 rounds of compression.