Glossary
HASHING

SHA-256

Secure Hash Algorithm 256-bit — the industry-standard cryptographic hash function. Used in TLS certs, Bitcoin, Git, and every modern integrity check.

SHA-256 (Secure Hash Algorithm 256-bit) is a member of the SHA-2 family (FIPS 180-4) that produces a 256-bit (64 hex character) digest. It’s the default cryptographic hash function for TLS certificates, Bitcoin proof-of-work, Git commit IDs, HMAC signatures, and every serious integrity or authentication use case.

Output Format

SHA-256("hello world") = b94d27b9934d3e08a52e52d7da7dabfac484efe37a5380ee9088f7ace2efcde9

Where SHA-256 Is Used

  • TLS certificate signatures — every modern cert is sha256WithRSAEncryption or ECDSA-with-SHA-256
  • Bitcoin proof-of-work — miners search for input strings whose SHA-256 hash starts with N zero bits
  • Git commit IDs — abbreviated to 7-40 hex chars in the CLI
  • JWT signatures — HMAC-SHA-256 is the default HS256 algorithm
  • File integrity — sha256sum, shasum -a 256

Security Status

No known practical attacks. Best known cryptanalysis remains theoretical — SHA-256 is expected to remain secure for the foreseeable future. NIST recommends it for classifications up to TOP SECRET.

Common Miss — Password Hashing

SHA-256 is not a password-hashing function. It’s fast by design — a modern GPU computes billions of SHA-256 hashes per second, letting attackers brute-force passwords rapidly. Use bcrypt or Argon2 for passwords.

Generate SHA-256 and other hashes with the hash generator.

Check the MD5 glossary entry, the SHA-512 entry, and the bcrypt entry for password use cases.

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