基于理性信任模型的理性委托计算协议

传统的委托计算需要额外开销验证计算结果的正确性，导致委托计算效率较低、开销较大.针对此问题，结合博弈论与理性信任建模（rational trust modeling，简称RTM）的思想，提出了基于理性信任模型的理性委托计算协议.通过设置恰当的效用函数，激励计算方诚实执行协议，以此来保证计算结果的可靠性.首先，基于理性信任建模的思想构造理性信任模型，将服务器的生存周期作为效用函数的参数，设计满足委托计算参与者利益的效用函数，并分析协议中参与者的行为策略，当参与者采取“诚实”策略时，可以得到理性委托计算的纳什均衡点；其次，利用改进的NTRU （number theory research unit）公钥密码体制实现速度快、安全性高、具有抵抗量子计算攻击的能力的优点，结合Pedersen承诺方案，设计理性委托计算协议；最后，从正确性、安全性与性能这3个方面对协议进行分析，并通过实验证明生存周期对参与者效用的影响.结果表明，该协议可有效保证计算结果的可靠性.

Rational Delegation Computing Protocol Based on Rational Trust Model

It needs supernumerary overhead to prove the correctness of computation results in traditional delegation computing, that cause less efficient and high overhead. This study addresses these problems, proposes a rational delegation computing protocol based on rational trust model by combining the thinking of game theory and rational trust modeling. In order to ensure the reliability of computation results, appropriate utility function incentive calculator is set up to execute protocol honestly. Firstly, construct the rational trust model based on the thinking of rational trust modeling. The lifetime of server is taken as parameter to design the utility function which contented profit of participants of delegation computing; analyze behavior strategy of participants in protocol further, when they take "honest" strategy, they can earn the point of Nash equilibrium. Secondly, design rational delegation computing protocol by combining Pedersen commitment scheme and NTRU public key cryptosystem, with the advantage of high speed, high level security, and ability of resistant to quantum computing attacks. Finally, this protocol is analyzed from three aspects:correctness, security, and performance, and affection of the lifetime on the utility of participants is proven through experiment, the outcome shows reliability of computation results can be ensured effectively by the proposed protocol.