An Efficient and Secure Weighted Threshold Signcryption Scheme

Abstract

Threshold cryptosystems are well suited for the application of group-oriented collaborations which is of such a nature that specific cooperation should be established in connection with a number of organizational tasks, such as multigroup computation, threshold signature, and electronic information transfer. Over the years many researchers have made salient contributions to the concept of allowing group members to sign or encrypt digital messages on behalf of the entire group. Yet almost all the group-oriented signature or encryption cryptosystems have been developed on the premise that members of the party have the same weights (fixed-size thresholds) and the tasks (shared secrets), cannot be adjusted. This study proposes a new weighted threshold signcryption scheme based on elliptic curve cryptography (ECC) with a dynamic knapsack-type technique and the Chinese remainder theorem (CRT) to customize its weight values of group members in such a way that they are appropriately arranged to perform a more flexible group-oriented signcryption task on behalf of a group.