Fair multi-party coin toss protocols are fundamental to many cryptographic applications. While Cleve’s celebrated result (STOC’86) showed that strong fairness is impossible against half-sized coalitions, recent works have explored a relaxed notion of fairness called Cooperative-Strategy-Proofness (CSP-fairness). CSP-fairness ensures that no coalition has an incentive to deviate from the protocol. Previous research has established the feasibility of CSP-fairness against majority-sized coalitions, but these results focused on specific preference structures where each player prefers exactly one outcome out of all possible choices. In contrast, real-world scenarios often involve players with more complicated preference structures, rather than simple binary choices. In this work, we initiate the study of CSP-fair multi-party coin toss protocols that accommodate arbitrary preference profiles, where each player may have an unstructured utility distribution over all possible outcomes. We demonstrate that CSP-fairness is attainable against majority-sized coalitions even under arbitrary preferences. In particular, we give the following results:

错误:搜索内容不能为空,请输入英文关键词
错误:关键词超出字数限制,请精简
高级检索

Game-Theoretically Fair Coin Toss with Arbitrary Preferences

  • Forest Zhang,
  • Ke Wu

摘要

Fair multi-party coin toss protocols are fundamental to many cryptographic applications. While Cleve’s celebrated result (STOC’86) showed that strong fairness is impossible against half-sized coalitions, recent works have explored a relaxed notion of fairness called Cooperative-Strategy-Proofness (CSP-fairness). CSP-fairness ensures that no coalition has an incentive to deviate from the protocol. Previous research has established the feasibility of CSP-fairness against majority-sized coalitions, but these results focused on specific preference structures where each player prefers exactly one outcome out of all possible choices. In contrast, real-world scenarios often involve players with more complicated preference structures, rather than simple binary choices. In this work, we initiate the study of CSP-fair multi-party coin toss protocols that accommodate arbitrary preference profiles, where each player may have an unstructured utility distribution over all possible outcomes. We demonstrate that CSP-fairness is attainable against majority-sized coalitions even under arbitrary preferences. In particular, we give the following results: