Forward-secure identity-based signature with efficient revocation

ABSTRACT

The security of traditional identity-based signature (IBS) is totally built upon the assumption that the private key is absolutely secure. However, with the increasing use of mobile and unprotected devices in today's cryptosystems, the threat of key exposure represents a more serious and realistic concern. To mitigate the damage of key exposure in the setting of IBS, we propose to integrate key evolution and user revocation into IBS, and present forward-secure identity-based signature with user revocation (FS-RIBS). Specifically, we formalize the syntax and security definition of FS-RIBS, and give a concrete construction. The proposed scheme is proven secure in the standard model under a q-type complexity assumption. To demonstrate the merits of our scheme, we theoretically analyse its performance by comparing it with other related works. Moreover, we provide an implementation and the corresponding timing results of our scheme to show its practicability.

KEYWORDS:

• Cryptography
• identity-based signature
• key exposure
• forward security
• userrevocation

2010 AMS SUBJECT CLASSIFICATIONS:

• 94A60
• 68P25

Acknowledgments

We thank the anonymous reviewers for their helpful comments and suggestions.

Disclosure statement

No potential conflict of interest was reported by the authors.

Notes

1. Throughout the proof, the algorithm $\mathcal{B}$ needs to randomly guess the adversary $\mathcal{A}$'s behaviours, and has to abort the simulation if its guess is convinced to be wrong. To simplify the description, we assume that$\mathcal{B}$'s guess is always correct. At the end of the simulation, we will discuss the probability that such an assumption holds.

2. By the restrictions placed on $\mathcal{A}$'s queries, we have that $t\ne t^{\ast }$

Additional information

Funding

This work was supported in part by the National Basic Research Program of China (973 Program) [grant number 2012CB315905], in part by the National Nature Science Foundation of China [grant numbers 61502527 and 61379150], and in part by Foundation of Science and Technology on Information Assurance Laboratory [grant number KJ-14-004].