Title
PIR with Compressed Queries and Amortized Query Processing
Abstract
Private information retrieval (PIR) is a key building block in many privacy-preserving systems. Unfortunately, existing constructions remain very expensive. This paper introduces two techniques that make the computational variant of PIR (CPIR) more efficient in practice. The first technique targets a recent class of CPU-efficient CPIR protocols where the query sent by the client contains a number of ciphertexts proportional to the size of the database. We show how to compresses this query, achieving size reductions of up to 274X. The second technique is a new data encoding called probabilistic batch codes (PBCs). We use PBCs to build a multi query PIR scheme that allows the server to amortize its computational cost when processing a batch of requests from the same client. This technique achieves up to 40× speedup over processing queries one at a time, and is significantly more efficient than related encodings. We apply our techniques to the Pung private communication system, which relies on a custom multi-query CPIR protocol for its privacy guarantees. By porting our techniques to Pung, we find that we can simultaneously reduce network costs by 36× and increase throughput by 3X.
Year
DOI
Venue
2018
10.1109/SP.2018.00062
2018 IEEE Symposium on Security and Privacy (SP)
Keywords
DocType
ISSN
private information retrieval,batch codes,PIR,FHE,multi query PIR
Conference
1081-6011
ISBN
Citations 
PageRank 
978-1-5386-4354-9
8
0.74
References 
Authors
55
4
Name
Order
Citations
PageRank
Sebastian Angel1318.25
Hao Chen2464.39
Kim Laine3939.83
Srinath T. V. Setty438416.40