This work looks like it might be of interest to readers of this list. Ravi --- On Tue, 24 Sep 1996 14:52:08 -0700 (PDT) Scott Dakins <sjdakins@cs.washington.edu> wrote: UNIVERSITY OF WASHINGTON Seattle, Washington 98195 Department of Computer Science and Engineering Box 352350 (206) 543-1695 COLLOQUIUM SPEAKER: Benny Chor, Technion, Haifa, Israel TITLE: Private Information Retrieval DATE: Wednesday, September 25, 1996 TIME: 3:30 pm PLACE: 422 Sieg Hall HOST: Richard Karp ABSTRACT: Publicly accessible databases are an indispensable resource for retrieving up to date information. But they also pose a significant risk to the privacy of the user, since a curious database operator can follow the user's queries and infer what the user is after. Indeed, in cases where the users' intentions are to be kept secret, users are often cautious about accessing the database. It can be shown that when accessing a single database, to completely guarantee the privacy of the user, the whole database should be downloaded , namely $n$ bits should be communicated (where $n$ is the number of bits in the database). In this work, we investigate whether by replicating the database, more efficient solutions to the private retrieval problem can be obtained. We describe schemes that enable a user to access $k$ replicated copies of a database ($k\geq 2$) and privately retrieve information stored in the database. This means that each individual database gets no information on the identity of the item retrieved by the user. These schemes use the replication to gain substantial saving. In the talk, I will describe the original work on this topic (joint work with Oded Goldreich, Eyal Kushilevitz, and Madhu Sudan), as well as recent developments in this area. Refreshments to follow. Email: talk-info@cs.washington.edu Info: http://www.cs.washington.edu ---------------End of Original Message-----------------