Bayesian mechanism for rational secret sharing scheme

Abstract

We consider the cooperation of rational parties in secret sharing. We present a new methodology for rational secret sharing both in two-party and multi-party settings based on Bayesian game. Our approach can resolve the impossible solutions to a rational secret sharing model. First, we analyze the 2-out-of-2 rational secret sharing using Bayesian game, which makes us able to consider different classes of the protocol player (for “good” and “bad” players) and model attributes such as any other parties’ preferences and beliefs that may affect the outcome of the game. Thus, the new model makes us able to reason rational secret sharing from the perspective of Bayesian rationality, a notion that may be in some scenarios more appropriate than that defined as per pure rational. According to these analyses, we propose a Bayesian rational protocol of 2-out-of-2 secret sharing. Also, our techniques can be extended to the case of t-out-of-n Bayesian rational secret sharing easily. Our protocol is adopted only by the parties in their decision-making according to beliefs and Bayes rule, without requiring simultaneous channels and can be run over asynchronous networks.

摘要

创新点

本文研究秘密共享中理性参与者的合作问题。 基于贝叶斯博弈提出适用于两方和多方环境下的理性密秘共享的新方法, 该方法能解决理性密秘共享模型中的一些难以解决的问题。 首先, 应用贝叶斯博弈分析门限(2, 2)理性秘密共享方案, 该方案能考虑不同类型的协议参与者(“诚实的”和“恶意的”参与者)以及从参与者的偏好、 信念等属性建模, 这些属性能影响理性秘密共享协议的博弈的结果。 该模型从贝叶斯理性的角度合理的刻画理性秘密共享, 较从纯理性的角度分析理性秘密共享更符合实际应用。 基于这些分析, 我们提出贝叶斯理性秘密共享协议, 该技术能容易的扩展到门限(t, n)贝叶斯理性秘密共享的情况而不影响其安全性能。 而且, 我们的协议仅需各参与者基于他们的信念和贝叶斯规则进行决策而不要求同步信道, 能在异步网络上运行。