DE-RSTC: A rational secure two-party computation protocol based on direction entropy
This work addresses fairness issues in rational secure two-party computation, an incremental improvement in cryptographic protocols for secure multi-party computation.
The paper tackles the problem of rational parties maliciously executing protocols in secure two-party computation, which undermines fairness and correctness, by proposing a direction entropy-based solution that leverages game theory and mutual information to construct utility functions, proving the protocol achieves Nash equilibrium and showing through experiments that honest players obtain higher utility.
Rational secure multi-party computation (RSMC) means two or more rational parties to complete a function on private inputs. In the process, the rational parties choose strategies to maximize utility, which will cause players to maliciously execute the protocol and undermine the fairness and correctness of the protocol. To solve this problem, we leverage game theory to propose the direction entropy-based solution. First, we utilize the direction vector of the direction entropy to examine the player's strategy uncertainty and quantify its strategy from different dimensions. Specifically, when parties choose a cooperation strategy, the direction vector is positive, and the information transmitted is positive, conversely, it is negative information. Then, we provide mutual information to construct new utility functions for the players. What's more, we measure the mutual information of players to appraise their strategies. Finally, we prove in detail the protocol we gave, and the result show that the fairness problem in rational secure two-party computation. We also prove that the proposed protocol reaches the Nash equilibrium. Furthermore, we conduct experiments using mutual information to construct utility, and the results show that the utility obtained when the player is honest will be higher.