ProvablyHero
18+

What is a hash (SHA-256)?

Article updated: Portrait of KirillKirill

Real example:

SHA-256("hello") = 2cf24dba5fb0a30e26e83b2ac5b9e29e1b161e5c1fa7425e73043362938b9824
SHA-256("Hello") = 185f8db32271fe25f561a6fc938b2e264306ec304eda518007d1764826381969
One capital letter, an entirely different result.

Why provably fair needs it. Before you bet, the casino shows you the SHA-256 hash of its secret server seed. That locks the seed in place: if the casino later revealed a different seed, its hash wouldn't match. And because a hash can't be reversed, seeing it in advance tells you nothing about the results.

In ProvablyHero tools

The hash checker on provably fair and every verifier run SHA-256 in your browser.

FAQ

Can a hash be cracked to get the server seed?
Not in practice. Server seeds are long random values; recovering one from its SHA-256 hash is beyond any existing computer.
  • What is a server seed?The server seed is the casino's secret random value behind every result. How it's committed with a hash, revealed on rotation and used to verify bets.
  • What is HMAC?HMAC mixes a secret key with a message into one hash. How crypto casinos use HMAC-SHA256 to combine server seed, client seed and nonce into a result.
  • What is seed rotation?Seed rotation replaces your active seed pair and reveals the old server seed, so you can verify past bets. When to rotate and what changes.
  • What "provably fair" actually meansProvably fair in plain words: server seed, client seed, nonce and hash. A walkthrough on a real casino's algorithm, and what it can't prove.