Collusion-Resistant Group Key Management Using Attribute-Based Encryption

This paper illustrates the use of ciphertext-policy attributebased encryption (CP-ABE), a recently proposed primitive, in the setting of group key management. Specifically, we use the CP-ABE scheme of Bethencourt, Sahai and Waters to implement flat table group key management. Unlike past implementations of flat table, our proposal is resistant to collusion attacks. We also provide efficient mechanisms to refresh user secret keys (for perfect forward secrecy) and to delegate managerial duties to subgroup controllers (for scalability). Finally, we discuss performance issues and directions for future research.