Robust distributed key issuing protocol for identity based cryptography

In this paper, we propose a robust distributed threshold key transfer protocol or issuing protocol that solves the key escrow problem in identity-based approach. We use threshold cryptographic techniques in each phase of the algorithm such as in system public key setup, key issuing, key securing and private key reconstruction. Our protocol is robust means even t KPA's (out of n = 21 + 1) are corrupted or dishonest the user recover the private key. This protocol can be efficient even if the communication between authorities (KGC and KPAs) is insecure. This approach is useful and offer benefits that are in identity-based techniques, while eliminating key escrow from the setup. In this protocol, either KGC or KPA cannot cheat the users to obtain their private keys. Security analysis of proposed protocol and active adversary assumptions are also presented.