ProvablyHero
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What is a server seed?

Article updated: Portrait of KirillKirill

The life of a server seed:

  1. Generated by the casino.
  2. Committed - you're shown its SHA-256 hash before your first bet.
  3. Used for every bet until rotation.
  4. Revealed when you rotate. Now you can hash it, compare with the commitment, and recompute every bet.

Two properties make this work. The hash proves the seed wasn't swapped after you played. And keeping the seed secret until rotation stops anyone, including you, from knowing results in advance.

Common mistake when verifying: pasting the hashed server seed instead of the revealed one. The verifier needs the plain seed.

In ProvablyHero tools

Verifiers check the revealed seed against its hash first, then replay the bets.

  • What is a client seed?The client seed is your input into every provably fair result. What it does, why it protects you, and why changing it never changes your odds.
  • 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 is a hash (SHA-256)?A hash is a one-way fingerprint of data. How SHA-256 lets a casino commit to a secret seed before you bet, with a real example you can check.
  • 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.