Glossary

Hash (Cryptographic)

A one-way mathematical function that converts any input into a fixed-length output — used in provably fair crash games to commit the crash point before the round without revealing the underlying seed.

In provably fair crash games, the hash is the public commitment to the round’s outcome. Displaying the hash before the round starts proves the crash point was fixed in advance — while keeping the actual crash point secret until after the round.

Why hashing works for commitments

A cryptographic hash function has three properties that make it ideal for provably fair systems:

Deterministic: The same input always produces the same output. SHA-256("seed123") = "abc789..." every time.

One-way (pre-image resistant): Given the hash "abc789...", you cannot compute the input "seed123". Reversing the function is computationally infeasible.

Collision resistant: Two different inputs cannot produce the same hash output. The casino cannot generate a different seed that happens to hash to the pre-committed value.

How it prevents manipulation

Without the hash commitment, a casino could theoretically:

  1. Start a round
  2. Wait to see when players cash out
  3. Set the crash point just below the last cash-out to maximize house take

The hash prevents this: the crash point is encoded in the hash before the round. Changing the crash point mid-round would produce a different hash — detectable by any player who verifies.

The SHA-256 function

Most crash game providers use SHA-256 (Secure Hash Algorithm 256-bit). The output is always exactly 256 bits (64 hexadecimal characters), regardless of input length.

SHA-256("x") → "2d711642b726b04401627ca9fbac32f5c8530fb1903cc4db02258717921a4881"
SHA-256("X") → "4b68ab3847feda7d6c62c1fbcbeebfa35eab7351ed5e78f4ddadea5df64b8015"

One character change in the input produces a completely different output — the hash is sensitive to any modification.

What hashes do not prove

A hash proves the crash point was committed in advance. It does not prove the game is fair in terms of distribution — a casino could theoretically commit to 1.00x crash points on every round. The RTP and distribution are separate properties verified by mathematical analysis of outcomes over many rounds, not by a single hash.

  • Seed — the value being hashed
  • Provably Fair — the system hashes are part of
  • RNG — the broader randomness system

Related terms

seedprovably fairrngcrash point