A Secure and Comparable Text Encryption Algorithm

TL;DR

This paper introduces a text encryption algorithm leveraging the subset sum problem, enabling semantic comparison of encrypted messages without decryption, facilitating privacy-preserving similarity assessments.

Contribution

The novel encryption method allows semantic comparison of messages directly in encrypted form, a new approach for privacy-preserving communication and collaboration.

Findings

Encryption correlates with message similarity

Enables comparison without decryption

Potential application in secure collaboration

Abstract

This paper discloses a simple algorithm for encrypting text messages, based on the NP-completeness of the subset sum problem, such that the similarity between encryptions is roughly proportional to the semantic similarity between their generating messages. This allows parties to compare encrypted messages for semantic overlap without trusting an intermediary and might be applied, for example, as a means of finding scientific collaborators over the Internet.