INFORMATICA Informatica 1822-8844 0868-4952 0868-4952 Vilnius University Institute of Mathematics and Informatics Akademijos 4, LT-08663 Vilnius, Lithuania INFO578 10.15388/Informatica.2005.088 Research Article An Improvement of the Ateniese’s Verifiable Encryption Protocol Popescu Constantin cpopescu@uoradea.ro * Department of Mathematics, University of Oradea, Str. Armatei Romane 5, Oradea, Romania

The author is presently at “Centre for Quantifiable Quality of Service in Communication Systems” (Q2S), NTNU, Trondheim, Norway. The centre is appointed Centre of Excellence by The Research Council of Norway. It is financed by the Research Council, NTNU and UNINETT, and supported by Telenor.

 2005 16 1 121 130 1 11 2003 © 2005 Institute of Mathematics and Informatics, Vilnius 2005 Open access article under the CC BY license.

Verifiable encryption is a primitive that can be used to build extremely efficient fair exchange protocols where the items exchanged represent digital signatures. Such protocols may be used to digitally sign contracts on the Internet. This paper presents an efficient protocol for verifiable encryption of digital signatures that improves the security and efficiency of the verifiable encryption scheme of Ateniese. Our protocol can be applied to group signatures, key escrow and publicly verifiable secret and signature sharing to prove the fairness.

 cryptographic protocols verifiable encryption security digital signatures