Abstract:This paper studies the Verifiable Signature Sharing (VΣS) introduced by Franklin and Reiter, which enables the recipient of a signature to share it among n proxies so that a subset of them can reconstruct it later. By the use of secure distributed key generation based on discrete-log, threshold cryptosystems and verifiable secret sharing scheme, new protocols for RSA VΣS are presented. The protocols are efficient and provable secure and can tolerate the malicious behavior of up to half of the proxies.