Keith Frikken, Hidden Access Control Policies with Hidden Credentials

In an open environment such as the Internet, the decision to collaborate with a stranger (e.g., by granting access to a resource) is often based on the characteristics (rather than the identity) of the requester, via digital credentials: Access is granted if Alice's credentials satisfy Bob's access policy. The literature contains many scenarios in which it is desirable to carry out such trust negotiations in a privacy-preserving manner, i.e., so as minimize the disclosure of credentials and/or of access policies. Elegant solutions were proposed for achieving various degrees of privacy-preservation through minimal disclosure. We present efficient protocols that protect both sensitive credentials and sensitive policies. That is, Alice gets the resource only if she satisfies the policy, Bob does not learn anything about Alice's credentials (not even whether Alice gained access or not), and Alice learns neither Bob's policy structure nor which credentials caused her to gain access. About the speaker: Keith Frikken is a doctoral student in computer science at Purdue University. His research interests are are in security and databases. His specific interests in security include: secure protocols, privacy, and access control.