Server-Assisted Forward-Secure Threshold Signature

• Published in: Wuhan University journal of natural sciences Vol. 13; no. 4; pp. 421 - 424
• Main Authors: Yu, Jia, Kong, Fanyu, Hao, Rong, Li, Xuliang
• Format: Journal Article
• Language: English; Chinese
• Published: Heidelberg Wuhan University 01.08.2008
• Subjects: Biomedical and Life Sciences; Computer Science; Life Sciences; Materials Science; Workshop on Semantic Web and Ontology 2008 (SWON 2008); 加密技术; 发出安全性; 密码学; 阈值符号; China, People's Rep., Hubei Prov., Wuhan; server-assisted cryptography; threshold signature; forward security; TN 918.4
• ISSN: 1007-1202; 1993-4998
• DOI: 10.1007/s11859-008-0408-6

Forward secure signature can protect the security of signatures previous to the key exposure. Server-assisted signature is a special digital signature in which the signer allies one server to produce the signatures. In this paper, server-assisted for-ward-secure threshold signature is proposed. The system is composed of n1 servers and n2 users. Each user and each server holds a partial secret, respectively. To produce a valid signature, users and servers need to cooperate to complete the work. The partial secrets of the users and servers are updated by a one-way function at regular intervals, while the public key is always fixed. Even if all the current partial secrets are exposed, the signatures pertaining to previous periods are still valid.