Abstract

Recently, Wu et al. proposed a time-bound hierarchical key assignment (TBHKA) scheme which supports discrete time periods. In their scheme, it fused RSA and pairing-based cryptosystems and is provably secure. In this paper, we demonstrate a weakness of Wu et al.'s TBHKA scheme, ie. a collusion attack. Any two users can collude to compute an encryption key to access some class in an un-subcribing time period.

Talk to us

Join us for a 30 min session where you can share your feedback and ask us any queries you have

Schedule a call

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.