Identity-based threshold ring signature without pairings

Identity-based(ID-based) threshold ring signature has rapidly emerged in recent years and many schemes have been proposed until now. However, most of these ID-based threshold ring signatures are constructed from bilinear pairings, a powerful but computationally expensive primitive. Hence, ID-based threshold ring signature without pairing is of great interest in the field of cryptography. In this paper, we propose an ID-based threshold ring signature scheme without pairings. The proposed scheme is proven to be existential unforgeable against adaptive chosen message-and-identity attack under the random oracle model, assuming the hardness of factoring.