Security

Hashing

A one-way transformation that turns data like a password into a fixed fingerprint you can't reverse.

Hashing is a meat grinder: you can turn a steak into mince, but never mince back into a steak. That's exactly why passwords must be hashed before storage — if your database leaks, attackers get useless fingerprints instead of real passwords. Use a slow, salted algorithm built for this (bcrypt or Argon2), never a fast one like MD5 or SHA-256 alone, and note that hashing is one-way and different from encryption (which is reversible). If you ever see AI code storing a raw password in a column, that's a stop-the-line bug.