A crucial element of distributed cryptographic file systems are key management solutions that allow for flexible but secure data sharing. We consider efficient key management schemes for cryptographic file systems using lazy revocation. We give rigorous security definitions for three cryptographic schemes used in such systems, namely symmetric encryption, message-authentication codes and signature schemes. Additionally, we provide generic constructions for symmetric encryption and message-authentication codes with lazy revocation using key-updating schemes for lazy revocation, which have been introduced recently. We also give a construction of signature schemes with lazy revocation from identity-based signatures. Finally, we describe how our constructions improve the key rotation mechanism in the Plutus file system.
By: Michael Backes, Christian Cachin and Alina Oprea
Published in: RZ3628 in 2005
LIMITED DISTRIBUTION NOTICE:
This Research Report is available. This report has been submitted for publication outside of IBM and will probably be copyrighted if accepted for publication. It has been issued as a Research Report for early dissemination of its contents. In view of the transfer of copyright to the outside publisher, its distribution outside of IBM prior to publication should be limited to peer communications and specific requests. After outside publication, requests should be filled only by reprints or legally obtained copies of the article (e.g., payment of royalties). I have read and understand this notice and am a member of the scientific community outside or inside of IBM seeking a single copy only.
Questions about this service can be mailed to reports@us.ibm.com .