A Voting Scheme in Blockchain Based on Threshold Group Signature

Traditional voting schemes are used for the credit evaluation and authentication. During the voting process, the contents need to be verified through the signature algorithms. Traditional signature schemes for voting scenes exist several drawbacks such as distrust of central nodes for the group signature and inefficiency for the ring signature. A trusted center selection scheme is proposed based on Dynamic Bayesian Network, which can be adapted in the isomerized blockchain. By introducing the historical interaction window, the aging factor, and the penalty factor, the adaptive trusted metrics can be obtained through aggregating the direct credibility and the indirect credibility. A new threshold group signature scheme is introduced through collaboration between users and the trusted centers. In order to protect the user identities, the blinding process is proposed. In case of compromising, the trusted centers create redundant backup, and can be updated with the proposed selection scheme. Security analysis shows that the proposed signature, whose difficulty is equivalent to the discrete logarithm of the elliptic curve, achieves a high level of anonymity and can resist impersonation attacks. Computational complexity analysis shows that the new method with low computational cost and transmission efficiency can be effectively adapted to the isomerized blockchain scene.