Threshold entrusted undeniable signature

Abstract

Entrusted undeniable signatures are like undeniable signatures, except that the disavowal protocol can only be run by a court in order to resolve a formal dispute. This paper introduces threshold entrusted undeniable signature scheme without trusted center. It is shown how the power to run a disavowal protocol of entrusted undeniable signature can be distributed to n agents such that any t of these can verify a signature. This facility is useful to solve "lie detector" problem of undeniable signatures. © Springer-Verlag Berlin Heidelberg 2005.