SM9-DTRS: a dynamic threshold ring signature scheme based on SM9 algorithm

Abstract In distributed scenarios such as electronic voting and blockchain, signature schemes require high anonymity, collusion resistance, and efficiency. Traditional ring signatures struggle to balance dynamism and security, while dynamic threshold ring signature research remains underdeveloped. This paper proposes SM9-DTRS, a dynamic threshold ring signature scheme based on the SM9 algorithm. It adopts a dynamic threshold mechanism and reservoir sampling for real-time signer set adjustment, and optimizes bilinear pairings via precomputation. Experimental results show SM9-DTRS achieves 55.66 ms signature generation time (44.46% reduction) and 148.93 ms verification time (21.80% reduction) compared to similar schemes. Its signature length is (256 t + 768)-bit, scaling linearly with threshold t (instead of ring size n in traditional schemes), making it suitable for bandwidth-constrained environments. Under the random oracle model, SM9-DTRS is proven unforgeable, anonymous, and collusion-resistant based on the q -SDH assumption.