Convertible Authenticated Encryption Scheme Without Using Conventional One‐Way Function

Article type: Research Article

Authors: Chien, Hung‐Yu

Affiliations: Department of Information Management, Chaoyang University of Technology, Taichung, Taiwan, ROC, e‐mail: redfish6@ms45.hinet.net

Abstract: An authenticated encryption allows the designated recipient to verify the authenticity while recovering the message. To protect the recipient's benefit in case of a later dispute, a convertible authenticated encryption scheme allows the recipient to convert the authenticated encryption into an ordinary signature so that it becomes a publicly verifiable. This paper shows a universal forgery attack on Araki et al.'s convertible authenticated encryption scheme, and proposes a new convertible authenticated encryption scheme. Without using any conventional one‐way function, the proposed scheme simplifies its security assumption on only a public hard problem – the discrete logarithm problem.

Keywords: authenticated encryption, discrete logarithm, one‐way function

Journal: Informatica, vol. 14, no. 4, pp. 445-454, 2003