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01302841 Catalano, Dario Gennaro, Rosario New efficient and secure protocols for verifiable signature sharing and other applications. Krawczyk, Hugo (ed.), Advances in cryptology - CRYPTO '98. 18th annual international cryptology conference, Santa Barbara, CA, USA, August 23--27, 1998. Proceedings. Berlin: Springer. Lect. Notes Comput. Sci. 1462, 105-120 (1998). 1998 Berlin: Springer EN verifiable signature sharing threshold cryptosystem undeniable signature scheme binding RSA cryptosystems Summary: Verifiable signature sharing (V$\Sigma$S) enables the recipient of a digital signature, who is not necessarily the original signer, to share such signature among $n$ proxies so that a subset of them can later reconstruct it. The original RSA and Rabin V$\Sigma$S protocols were subsequently broken and the original DSS V$\Sigma$S lacks a formal proof of security. The authors present new protocols for RSA, Rabin and DSS V$\Sigma$S. Their protocols are efficient and provably secure and can tolerate the malicious behavior of up to half of the proxies. Furthermore the authors believe that some of their techniques are of independent interest. Some of the by-products of their main result are: a new threshold cryptosystem, a new undeniable signature scheme and a way to create binding RSA cryptosystems.