Time-Selective Convertible Undeniable Signatures

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Time-Selective Convertible Undeniable Signatures
Undeniable signatures were introduced in 1989 by Chaum and van Antwerpen to limit the self-authenticating property of digital signatures. An extended concept – the convertible undeniable signatures – proposed by Boyar, Chaum, Damg˚ard and Pedersen in 1991, allows the signer to convert undeniable signatures to ordinary digital signatures. We present a new efficient convertible undeniable signature scheme based on bilinear maps. Its unforgeability is tightly related, in the random oracle model, to the computational Diffie-Hellman problem and its anonymity to a non-standard decisional assumption. The advantages of our scheme are the short length of the signatures, the low computational cost of the signature and the receipt generation. Moreover, a variant of our scheme permits the signer to universally convert signatures pertaining only to a specific time period. We formalize this notion as the time-selective conversion.
Fabien Laguillaumie, Damien Vergnaud
Added 26 Jun 2010
Updated 26 Jun 2010
Type Conference
Year 2005
Authors Fabien Laguillaumie, Damien Vergnaud
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