Last Revealer Attack

Definition ∞ A last revealer attack is a vulnerability in commit-reveal protocols where the participant who reveals their committed value last gains an unfair advantage. This occurs by observing others’ revelations first, allowing the last revealer to adjust their strategy based on complete information. It undermines the fairness and integrity of the protocol. This attack exploits the sequential nature of the reveal phase.
Context ∞ This attack vector is a significant concern in the design and security auditing of decentralized applications and blockchain-based games that rely on commit-reveal schemes. Developers frequently implement countermeasures, such as forced simultaneous reveals or cryptographic techniques like zero-knowledge proofs, to mitigate this risk. News articles about protocol exploits or security audits often reference the last revealer attack when discussing vulnerabilities in smart contracts.