Secure and Efficient Threshold Key Issuing Protocol for ID-based Cryptosystems.

Abstract

Key issuing protocols deal with overcoming the two inherent problems: key escrow and secure channel requirement of the identity based cryptosystems. An efficient key issuing protocol enables the identity based cryptosystems to be more acceptable and applicable in the real world. We present a secure and efficient threshold key issuing protocol. In our protocol, neither KGC nor KPA can impersonate the users to obtain the private keys and thus it achieves the trust level III [16]. The protocol is secure against replay, man-in-the-middle and insider attacks.