A rational threshold signature with hierarchical structure

A rational threshold signature with hierarchical structure

Xiurong Li 1, Yongquan Cai2, Yali Liu 3


1,2 College of Computer Science and Technology, Beijing University of Technology, Beijing 100124, China

3 School of Science and Technology, Beijing City University, Beijing, China

Rational secret sharing module combines Game theory with cryptography by taking rational behavior into consideration thus has a wider range of application. We apply rational secret sharing into threshold signature so as to construct a hierarchical structure that is described by extended game. Dynamic game of complete information is applied into partial signature’s distribution and reconstruction phase where a probable value is calculated that can maximize the payoff. In each round of the game, secret key is iteratively generated in a way that any forge secret key will be detected by PKG system. Mixed strategy model is adopted instead of pure strategy model to prevent deviation, which is proved to be Nash equilibrium. Correctness and anti-deceive feature is proofed. The security is based on solving BDH problem in group so the scheme is high effective and chosen cipher text security.