Hashing

ELI5 — The Vibe Check

Hashing is a one-way blender for data. You throw a password in, it spits out a weird string of letters and numbers, and there's no way to reverse it. Every time you hash the same word, you get the exact same weird string — great for checking passwords without ever storing them.

Real Talk

Hashing is a one-way function that maps input data to a fixed-size digest (hash). It's deterministic but irreversible. Used for password storage, data integrity checks, and digital signatures. Common algorithms: SHA-256, bcrypt, Argon2.

Show Me The Code

// Hashing a password with bcrypt
import bcrypt from 'bcrypt';
const hash = await bcrypt.hash('myPassword123', 10);
console.log(hash); // '$2b$10$...' — irreversible
const match = await bcrypt.compare('myPassword123', hash); // true

When You'll Hear This

"We never store plain passwords — we store the hash." / "The file hash changed, so it was tampered with."