Security analysis and improvement for key issuing schemes in ID-based cryptography

Abstract

In this paper, we analyze some serious weakness for security of existing key issuing schemes in identity (ID)-based cryptosystems which were proposed in order to eliminate key escrow property and remove the need of secure channel, and describe some attacks for them. In addition, we present the improved key issuing protocols for each scheme with weakness, which can resist the attack and overcome key escrow problem.