CCSP Seminar:Yi-Peng Wei, "Cache-Aided Private Info. Retrieval with Unknown and Uncoded Prefetching"
Thursday, February 22, 2018
5:00 p.m.-6:30 p.m.
301 405 3661
Abstract: Private information retrieval (PIR) is a canonical problem to investigate the privacy of the contents downloaded from public databases. In the classical form of the problem, a user requests to download a message from $K$ messages from $N$ non-communicating databases such that no database can distinguish individually which message has been retrieved. A naive though inefficient PIR scheme is to download all of the $K$ messages from a database. Consequently, the aim of the PIR problem is to retrieve the desired message correctly by downloading as few bits as possible from the $N$ databases under the privacy constraint.
In this talk, we consider PIR from $N$ non-colluding and replicated databases when the user is equipped with a cache that holds an uncoded fraction $r$ from each of the $K$ stored messages in the databases. We assume that the databases are unaware of the cache content. We investigate $D^*(r)$, the optimal download cost normalized with the message size as a function of $K$, $N$, $r$.
Joint work with Karim Banawan and Prof. Sennur Ulukus.