A privacy-preserving broadcast encryption scheme with revocability

In secure content distribution systems, it is important to protect what is transmitted. For privacy purposes, another issue is the protection of the list of recipients. However, in most practical and commercial systems, providing complete recipient´s anonymity is not always desirable. There may be a need for the content owner to recover the identity of malicious users. This paper proposes a privacy-preserving broadcast encryption scheme offering a balanced trade-off between full traceability and user´s privacy.