Abstract
In EUROCRYPT 2002, Alwen et al. demonstrated that an identity-based hash proof system (IB-HPS) can be used to generate an identity-based encryption (IBE) scheme, which is secure against partial leakage of the decryption key of the target identity. However, in many real-world applications, the leakage is normally unbounded, and an adversary could violate the security of such cryptography schemes by performing continuous leakage attacks. Therefore, cryptography schemes are desirable to maintain their claimed security even in the continuous leakage setting. In this paper, we first design an improved IB-HPS called updatable IB-HPS (U-IB-HPS), which has an additional key update algorithm to embed some fresh randomness into the user's private key, ensuring that enough entropy is maintained in the updated keys. Then, we further use the U-IB-HPS to propose a generic construction of continuously leakage-resilient IBE schemes. Finally, an instantiation of the U-IB-HPS with anonymity is presented. As a result, our construction delivers an anonymous IBE scheme that is secure against continuous leakage of user's private key. The security of our proposed scheme has been proved in the random oracle model under the classic decisional bilinear Diffie–Hellman assumption, which is a standard static security assumption.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.