Attribute-Based Publishing with Hidden Credentials and Hidden Policies

With Hidden Credentials Alice can send policyencrypted data to Bob in such a way that he can decrypt the data only with the right combination of credentials. Alice gains no knowledge of Bob’s credentials in the process, and hence the name “Hidden Credentials.” Research on Hidden Credential systems has focused on messages sent to single recipients, where the sender needs to know the recipient’s pseudonym beforehand, and on Hidden Policies, where Bob learns as little information as possible about Alice’s policy for decrypting the message. Current schemes provide weak policy privacy — with non-interactive schemes, the recipient can learn parts of the policy, and with interactive schemes based on secure multiparty computation, a user can try different sets of credentials as input to gain knowledge of the policy after repeated decryption attempts. Furthermore, existing schemes do not support policies with negations efficiently. For example, a policy stating “Bob is not a stu...

• Type: Conference
• Year: 2007
• Where: NDSS
• Authors: Apu Kapadia, Patrick P. Tsang, Sean W. Smith
• Keywords: Computer Networks, Credentials, Hidden Credential Systems, NDSS 2007, Policy