A provable secure key-escrow-free identity-based signature scheme without using secure channel at the phase of private key issuance

Abstract

The identity-based cryptosystems furnish us with simplest key management procedures. Yet, they have a very slow adoption in cryptography due to the key escrow problem and the necessity of a secure channel between the user and the Private Key Generator (PKG) to transmit the created private key to the user. In this paper, we propose an identity-based signature scheme that not only solves the key escrow problem but also eliminates the requirement of the secure channel. The proposed scheme is secure against existential forgery under adaptively chosen message and ID attacks in the random oracle model assuming the hardness of the Computational Diffie�Hellmann Problem (CDHP). Furthermore, we compare the efficiency of our scheme to that of a similar established scheme.