UC Irvine

The problem of weakly-private information retrieval, is a variant of private information

retrieval, where the user wants to retrieve 1 out of K messages from a distributed storage

system with N servers that stores all K messages, and is willing to leak some information

of the identity of the desired message. In this work, we study the problem of weakly-private

information retrieval. A novel information leakage metric is proposed, and the capacity for

the setting of N = 2 servers, and arbitrary number of messages K is characterized. In

particular, in the capacity achieving scheme, designing the distribution of the non-uniformly

distributed noise Z turns out to be the key to achieve the capacity.