In this paper we propose new constructions for time-bound hierarchical key assignment schemes which are provably secure with respect to key indistinguishability. Our constructions use as a building block any provably-secure hierarchical key assignment scheme without temporal constraints and exhibit a tradeoff among the amount of private information held by each class, the amount of public data, the complexity of key derivation, and the computational assumption on which their security is based. Moreover, the proposed schemes support updates to the access hierarchy with local changes to the public information and without requiring any private information to be re-distributed.
Category / Keywords: Access control, key assignment, provable security, efficient key derivation. Date: received 22 Dec 2006, last revised 3 Jan 2007 Contact author: masucci at dia unisa it Available formats: Postscript (PS) | Compressed Postscript (PS.GZ) | PDF | BibTeX Citation Version: 20070103:181025 (All versions of this report) Discussion forum: Show discussion | Start new discussion