What is Hashing?

1 min read Updated 2026-02-05

A one-way function that converts data into a fixed-length string. Used for password storage (with algorithms like bcrypt or Argon2) and data integrity verification.

Understanding Hashing

Unlike encryption, hashing is irreversible by design. Cryptographic hash functions produce unique outputs for different inputs (collision resistance) and small input changes create completely different outputs (avalanche effect). Password hashing adds salt and is intentionally slow to resist brute-force attacks.

Examples

  • Storing password hashes instead of plaintext passwords
  • Verifying file integrity with SHA-256 checksums
  • Creating digital signatures
  • Generating unique identifiers from data

How to Prevent

  • Use bcrypt, Argon2, or scrypt for password hashing
  • Always use unique salts per password
  • Use SHA-256 or SHA-3 for integrity verification
  • Never use MD5 or SHA-1 for security purposes
  • Configure appropriate work factors for password hashing

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