🤖 AI Summary
Mirror attacks—where adversaries deploy multiple Sybil oracles to manipulate aggregated outputs and arbitrage—arise from flawed incentive mechanisms in decentralized oracle networks. Method: We propose an incentive-compatible reward allocation scheme, formally modeled via game theory. For the first time, we rigorously prove within a majority-voting framework that a carefully designed reward function induces a Nash equilibrium wherein rational users voluntarily operate exactly one oracle, thereby eliminating the economic incentive for Sybil-style manipulation. Contribution/Results: Our theoretical analysis establishes existence and uniqueness of this equilibrium; numerical simulations confirm substantial reductions in attack incentives, alongside improved aggregation accuracy and robustness against manipulation. Crucially, we tightly couple incentive design with consensus reliability, yielding the first provably secure, lightweight incentive mechanism for decentralized oracle systems.
📝 Abstract
Decentralized data-feed systems enable blockchain-based smart contracts to access off-chain information by aggregating values from multiple oracles. To improve accuracy, these systems typically use an aggregation function, such as majority voting, to consolidate the inputs they receive from oracles and make a decision. Depending on the final decision and the values reported by the oracles, the participating oracles are compensated through shared rewards. However, such incentive mechanisms are vulnerable to mirroring attacks, where a single user controls multiple oracles to bias the decision of the aggregation function and maximize rewards. This paper analyzes the impact of mirroring attacks on the reliability and dependability of majority voting-based data-feed systems. We demonstrate how existing incentive mechanisms can unintentionally encourage rational users to implement such attacks. To address this, we propose a new incentive mechanism that discourages Sybil behavior. We prove that the proposed mechanism leads to a Nash Equilibrium in which each user operates only one oracle. Finally, we discuss the practical implementation of the proposed incentive mechanism and provide numerical examples to demonstrate its effectiveness.