Security
What is SHA-256?
A cryptographic hash function producing a 256-bit digest, part of the SHA-2 family.
SHA-256 (Secure Hash Algorithm 256-bit) is part of the SHA-2 family designed by the NSA and published by NIST in 2001. It produces a 256-bit (32-byte) hash value, typically rendered as a 64-character hexadecimal string.
SHA-256 is considered cryptographically secure — no practical collision or pre-image attacks are known. It is widely used in TLS certificates, digital signatures, and Bitcoin's proof-of-work algorithm.
Properties
- Deterministic: same input always produces the same hash
- Avalanche effect: tiny input changes drastically alter the output
- One-way: computationally infeasible to reverse
- Collision resistant: practically impossible to find two inputs with the same hash
FAQ
Should I use SHA-256 for passwords?
No. SHA-256 is too fast for password hashing. Use bcrypt, scrypt, or Argon2, which are intentionally slow to resist brute-force attacks.
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