P4QS: A Peer to Peer Privacy Preserving Query Service for Location-Based Mobile Applications

TL;DR

This paper introduces P4QS, a peer-to-peer privacy-preserving query system for location-based mobile apps that enhances user privacy without trusted nodes, using distributed anonymization and encrypted message exchanges.

Contribution

The paper presents a novel distributed anonymizing protocol based on peer-to-peer architecture that eliminates the need for trusted nodes in location privacy preservation.

Findings

Successfully implemented and tested the protocol

Achieved efficient user privacy in location-based services

No trusted nodes required for anonymization

Abstract

The location-based services provide an interesting combination of cyber and physical worlds. However, they can also threaten the users' privacy. Existing privacy preserving protocols require trusted nodes, with serious security and computational bottlenecks. In this paper, we propose a novel distributed anonymizing protocol based on peer-to-peer architecture. Each mobile node is responsible for anonymizing a specific zone. The mobile nodes collaborate in anonymizing their queries, without the need not get access to any information about each other. In the proposed protocol, each request will be sent with a randomly chosen ticket. The encrypted response produced by the server is sent to a particular mobile node (called broker node) over the network, based on the hash value of this ticket. The user will query the broker to get the response. All parts of the messages are encrypted except the fields required for the anonymizer and the broker. This will secure the packet exchange over the P2P network. The proposed protocol was implemented and tested successfully, and the experimental results showed that it could be deployed efficiently to achieve user privacy in location-based services.