Cryptology ePrint Archive: Report 2005/040

Unfairness of a protocol for certified delivery

Juan M. Estevez-Tapiador and Almudena Alcaide

Abstract: Recently, Nenadi\'c \emph{et al.} (2004) proposed the RSA-CEGD protocol for certified delivery of e-goods. This is a relatively complex scheme based on verifiable and recoverable encrypted signatures (VRES) to guarantee properties such as strong fairness and non-repudiation, among others. In this paper, we demonstrate how this protocol cannot achieve fairness by presenting a severe attack and also pointing out some other weaknesses.

Category / Keywords: cryptographic protocols / fair exchange; non-repudiation; attacks

Publication Info: Technical report

Date: received 15 Feb 2005, last revised 16 Feb 2005

Contact author: jestevez at inf uc3m es

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Version: 20050216:190452 (All versions of this report)

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