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CoinLotto uses Chainlink VRF 2.5 ↗, an independent third-party verifiable-randomness service, for lottery winner selection. Chainlink VRF provides the verifiable random input. CoinLotto smart contracts determine the ticket set, the Prize Distribution model, and how the verified result is applied.

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How a draw receives randomness

When a lottery draw becomes available and is initiated, the CoinLotto smart contract requests randomness through Chainlink VRF.
  1. The draw request is recorded on-chain.
  2. Chainlink VRF returns a random value together with a cryptographic proof.
  3. The proof is verified on-chain before the random value can be used.
  4. The CoinLotto contract uses the verified random value to select winning ticket numbers under the lottery’s fixed Prize Distribution rules.
  5. The draw is finalized, the outcome becomes immutable, and the resulting prizes become claimable.

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Draw integrity

No CoinLotto operator, Creator, or participant can choose, replace, or alter the random value used for a completed draw. The protocol cannot finalize a winner selection until a verified Chainlink VRF response is received on-chain.

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Retry condition

If no Chainlink VRF response is received within 15 minutes, the draw can be retried. No winner selection occurs until a verified response is received on-chain.

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Verify a draw

Users can verify the draw request, the resulting on-chain transaction, and the finalized lottery state through a supported blockchain explorer.