Efficient Computationally Private Information Retrieval from Anonymity or Trapdoor Groups

A Private Information Retrieval (PIR) protocol allows a database user, or client, to obtain information from a data- base in a manner that prevents the database from knowing which data was retrieved. Although substantial progress has been made in the discovery of computationally PIR (cPIR) protocols with reduced communication complexity, there has been relatively little work in reducing the computational complexity of cPIR protocols. In particular, Sion [18] argues that existing cPIR protocols are slower than the trivial PIR protocol (in overall performance). In this paper, we present a new family of cPIR protocols with a variety of security and performance properties. Our protocols enable much lower CPU overhead for the database server. When the database is viewed as a bit sequence, only addition operations are performed by the database server. We can view our protocol as a middle ground between the trivial protocol (fastest possible computational complexity and slowest possible comm...

• Type: Journal
• Year: 2010
• Where: ISW
• Authors: Jonathan T. Trostle, Andy Parrish
• Keywords: Computational Complexity, Cpir Protocol, Information Technology, ISW 2010, Trapdoor Group