Digital signature, one of cryptographic primitives, provides the integrity, authentication and non-repudiation of messages. In the past decade, ID-based signature (IBS) based on bilinear pairings has attracted significant attention. And a large number of IBS schemes have been proposed and most of them are probabilistic. In the signing phase of those probabilistic IBS schemes, random numbers (or ephemeral secrets) are used to generate signatures. Ephemeral secrets could be compromised if they are pre-computed and stored in insecure memory. In such a case, one can reveal the private key of the signer from the corresponding signature, termed ephemeral secret leakage (ESL) attacks. In this article, we define a novel security notion for IBS schemes to capture ESL attacks. Based on this notion, we propose the first IBS scheme resistant to ESL attacks, called the leakage-free IBS scheme. Under the computational Diffie-Hellman assumption, we demonstrate that the proposed leakage-free IBS scheme is provably secure in the new security notion. When compared with the probabilistic IBS schemes, our scheme is demonstrated to have higher security with affordable price in performance.
All Science Journal Classification (ASJC) codes
- Computer Science(all)