Glen Nuckolls

Security Lab Seminar
Nov. 13, 2002

Certifying Data from Multiple Sources: Making Price Comparison Honest

Abstract:
Data integrity can be problematic when integrating and organizing information from many sources. In this talk I will describe efficient mechanisms that enable a group of owners to contribute data sets to an untrusted third-party publisher, who then answers users' queries. Each owner gets a proof from the publisher that his data is properly represented, and each user gets a proof that the answer given to them is correct. This allows owners to be sure that their data is being properly represented and for users to be sure they are getting correct answers. We show that a group of data owners can efficiently certify that an untrusted third party publisher has computed the correct digest of the owners collected data sets. Users can then verify that the answers they get from the publisher are the same as a fully trusted publisher would provide, or detect if they are not. Price comparison services are an excellent application of these results but there are numerous others. These results are an extension of earlier work on Authentic Publication which assumed that a single trusted owner certified all of the data.