SHA-256, An industry-standard cryptographic hash function that's part of the SHA-2 (Secure Hash Algorithm 2) family. Developed by the NSA in 2001 and standardized by NIST.
Technical Specifications
- Hash Length:
- 256 bit (64 hex characters)
- Security Level:
- Very high - Cryptographically secure
- Block Size:
- 512 bit
- Maximum Message Size:
- 2^64 - 1 bit
- Speed:
- High performance, hardware and software optimization available
Usage Areas
- Bitcoin and blockchain technologies
- Digital signatures and certificates (SSL/TLS)
- Password hashing (PBKDF2, bcrypt, etc.)
- Data integrity verification
- Git version control system
- Mercurial version control system
Features
- Same input always produces the same hash (deterministic)
- Impossible to derive original data from hash (one-way)
- Avalanche effect: Small input changes produce completely different hash
- Collision resistance: Two different inputs cannot produce the same hash (practically)
- Preimage resistance: Finding original data from hash is impossible
Standards and References
- FIPS PUB 180-4 (SHA-2 Standard)
- ISO/IEC 10118-3
- RFC 6234