ID-based key-insulated signature scheme with batch verifications and its novel application

For a digital signature scheme, loss of private keys will cause a devastating effect on e-commerce and Internet-based transaction applications in the present network environment. Key-insulated public-key system is introduced to reduce damage caused by private key exposure. Over the last few years, identity (ID)-based key-insulated cryptography using bilinear pairings has received much attention from cryptographic researchers. In this paper, we propose a new and efficient ID-based key-insulated signature scheme with batch verifications. As compared with the recently proposed ID-based key-insulated signature schemes, our scheme has the best performance for batch verifications. For security analysis, we demonstrate that the proposed scheme is a provably secure ID-based key-insulated signature in the random oracle model and under the computational Diffie-Hellman assumptionn. Meanwhile, to demonstrate the additional advantage of our ID-based key-insulated signature scheme, we present a novel application based on the proposed scheme, called ID-based proxy signature scheme with full delegation and time restriction. This new type of proxy signature scheme provides flexible management for the delegated proxy signers.