The Capacity of Single-Server Weakly-Private Information Retrieval
Artikel i vetenskaplig tidskrift, 2021

A private information retrieval (PIR) protocol guar- antees that a user can privately retrieve files stored in a database without revealing any information about the identity of the requested file. Existing information-theoretic PIR proto- cols ensure perfect privacy, i.e., zero information leakage to the servers storing the database, but at the cost of high download. In this work, we present weakly-private information retrieval (WPIR) schemes that trade off perfect privacy to improve the download cost when the database is stored on a single server. We study the tradeoff between the download cost and information leakage in terms of mutual information (MI) and maximal leak- age (MaxL) privacy metrics. By relating the WPIR problem to rate-distortion theory, the download-leakage function, which is defined as the minimum required download cost of all single- server WPIR schemes for a given level of information leakage and a fixed file size, is introduced. By characterizing the download- leakage function for the MI and MaxL metrics, the capacity of single-server WPIR is fully described.

information leakage

information-theoretic privacy


single server

Private information retrieval


Hsuan Yin Lin

Simula UiB

Siddhartha Kumar

Simula UiB

Eirik Rosnes

Simula UiB

Alexandre Graell I Amat

Chalmers, Elektroteknik, Kommunikation, Antenner och Optiska Nätverk

Simula UiB

Eitan Yaakobi

Technion – Israel Institute of Technology

IEEE Journal on Selected Areas in Information Theory

2641-8770 (eISSN)

Vol. 2 1 415-427

Distribuerad lagring för datalagring och trådlös leverans av data

Vetenskapsrådet (VR) (2016-04253), 2016-01-01 -- 2019-12-31.


Annan data- och informationsvetenskap

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