Toward Secure CB-Signcryption for Wireless Ad Hoc Networks

Abstract

Signcryption schemes can be regarded as extended digital signature schemes which further provide confidentiality. For those applications which have to simultaneously satisfy the security requirements of authenticity and confidentiality, signcryption schemes are better alternatives. Yet, a later repudiation dispute might occur, since the signcrypted message can only be verified by a designated receiving node for protecting the confidentiality. In this paper, we consider the secure data forwarding in wireless ad hoc networks (WANET) and propose a certificate-based signcryption, i.e., CB-signcryption, with provable security from the bilinear pairing cryptosystem. In case of a later dispute, our scheme allows the designated receiving node to announce the original signature for public arbitration without extra computation efforts. Moreover, the security requirement of confidentiality against indistinguishability under adaptive chosen-ciphertext attacks (IND-CCA2) and that of unforgeability against existential forgery under adaptive chosen-message attacks (EF-CMA) are proved in the random oracle model. With the efficiency of the computation cost, our proposed scheme is suitable for WANET.