Cryptanalysis and improvement of an online/offline signcryption scheme
Cunhua Li · Journal of Computer Applications · 2011
Liu's online/offline signcryption scheme(LIU J K,BAEK J,ZHOU J.Online/offline identity-based signcryption re-visited.Inscrypt'10: Proceedings of the 6th International Conference on Information Security and Cryptology.Berlin: Springer-Verlag,2010:90-102) was cryptanalyzed and improved in this paper.By studying the unforgeability of Liu's scheme,this paper proved that Liu's scheme would be not unforgeable against adaptive chosen message and identity attack.To overcome the security problem in Liu's scheme,a modified scheme was proposed,and the modified scheme was proved to be a secure Identity-based online/offline signcryption scheme.