Private Information Retrieval with Private Coded Side Information: The Multi-Server Case

Understand

In this paper, we consider the multi-server setting of Private Information Retrieval with Private Coded Side Information (PIR-PCSI) problem.

• In this problem, there is a database of $K$ messages whose copies are replicated across $N$ servers, and there is a user who knows a random linear combination of a random subset of $M$ messages in the database as side information.
• The user wishes to download one message from the servers, while protecting the identities of both the demand message and the messages forming the side information.
• We assume that the servers know the number of messages forming the user's side information in advance, whereas the indices of these messages and their coefficients in the side information are not known to any of the servers a priori.