Encrypted Federated Search Using Homomorphic Encryption

TL;DR

This paper presents a privacy-preserving federated search system for law enforcement that uses homomorphic encryption to enable secure, encrypted queries across distributed criminal databases without exposing sensitive data.

Contribution

It introduces a novel federated search approach utilizing homomorphic encryption, allowing encrypted queries to be executed across multiple agencies' databases while maintaining data privacy.

Findings

System effectively performs encrypted searches in real-time.

Ensures data privacy and regulatory compliance.

Demonstrates scalability and security in practical scenarios.

Abstract

The sharing of information between agencies is effective in dealing with cross-jurisdictional criminal activities; however, such sharing is often restricted due to concerns about data privacy, ownership, and compliance. Towards this end, this work has introduced a privacy-preserving federated search system that allows law enforcement agencies to conduct queries on encrypted criminal databases by utilizing Homomorphic Encryption (HE). The key innovation here is the ability to execute encrypted queries across distributed databases, without the decryption of the data, thus preserving end-to-end confidentiality. In essence, this approach meets stringent privacy requirements in the interests of national security and regulatory compliance. The system incorporates the CKKS and BFV scheme embedded within TenSEAL, with each agency holding its key pair in a centralized key management table. In this federated search, encrypted queries are computed on the server side, and only authorized clients can decrypt the computed results. The matching of agencies is flexible for working in real-time while at the same time being secure and scalable while preserving control over data and the integrity of the process. Experimental results demonstrate the model. This paper also provide the implementation code and other details.