원문정보
초록
영어
Certificateless public key cryptography (CL-PKC) is an appealing paradigm with the advantages of both conventional public key cryptosystem and ID-based cryptosystem because it avoids using certificates and eliminates the key escrow problem. Ring signcryption is an attractive primitive which allows one user to send a message anonymously, confidentially and authentically. Recently, Qi et al. proposed a novel certificateless ring signcryption scheme with bilinear pairings, and claimed the scheme is provably-secure in the random oracle model. In this paper, we reveal that Qi et al.’s scheme is not secure against both a Type I adversary and a Type II adversary. By giving specific attacks, we found it is unable to meet the fundamental requirements of confidentiality and unforgeability.
목차
1. Introduction
2. Preliminaries
2.1. Bilinear Pairings
2.2. Formal Definition of Certificateless Ring Signcryption
2.3. Security Requirements of Certificateless Ring Signcryption
3. Review of Qi et al.’s Certificateless Ring Signcryption Scheme
4. Cryptanalysis of Qi et al.’s CLRSC Scheme
4.1. Message Confidentiality Attack
4.2. Unforgeability Attack
5. Conclusions
Acknowledgements
References