Revocation and Tracing Schemes for Stateless Receivers

We deal with the problem of a center sending a message to a group of users such that some subset of the users is considered revoked and should not be able to obtain the content of the message. We concentrate on the stateless receiver case, where the users do not (necessarily) update their state from to session. We present a framework called the Subset-Cover framework, which abstracts a variety of revocation schemes including some previously known ones. We provide sufficient conditions that guarantees the security of a revocation algorithm in this class. We describe two explicit Subset-Cover revocation algorithms; these algorithms are very flexible and work for any number of revoked users. The schemes require storage at the receiver of and keys respectively ( is the total number of users), and in order to revoke users the required message lengths are of and keys respectively. We also provide a general traitor tracing mechanism that can be integrated with any Subset-Cover revocation s...

• Type: Conference
• Year: 2001
• Where: CRYPTO
• Authors: Dalit Naor, Moni Naor, Jeffery Lotspiech
• Keywords: CRYPTO 2001, Cryptology, Revocation, Revocation Algorithm, Revocation Scheme