Hidden Elo: Private Matchmaking through Encrypted Rating Systems

Computer Science > Cryptography and Security [Submitted on 27 Mar 2026] Hidden Elo: Private Matchmaking through Encrypted Rating Systems Mindaugas Budzys, Bin Liu, Antonis Michalas Matchmaking has become a prevalent part in contemporary applications, being used in dating apps, social media, online games, contact tracing and in various other use-cases. However, most implementations of matchmaking require the collection of sensitive/personal data for proper functionality. As such, with this work we aim to reduce the privacy leakage inherent in matchmaking applications. We propose H-Elo, a Fully Homomorphic Encryption (FHE)-based, private rating system, which allows for secure matchmaking through the use of traditional rating systems. In this work, we provide the construction of H-Elo, analyse the security of it against a capable adversary as well as benchmark our construction in a chess-based rating update scenario. Through our experiments we show that H-Elo can achieve similar accuracy to a plaintext implementation, while keeping rating values private and secure. Additionally, we compare our work to other private matchmaking solutions as well as cover some future directions in the field of private matchmaking. To the best of our knowledge we provide one of the first private and secure rating system-based matchmaking protocols. Comments: Accepted In Proceedings of the Sixteenth ACM Conference on Data and Application Security and Privacy (CODASPY 26) Subjects: Cryptography and Security (cs.CR) Cite as: arXiv:2603.26407 [cs.CR]   (or arXiv:2603.26407v1 [cs.CR] for this version)   https://doi.org/10.48550/arXiv.2603.26407 Focus to learn more Related DOI: https://doi.org/10.1145/3800506.3803498 Focus to learn more Submission history From: Mindaugas Budzys [view email] [v1] Fri, 27 Mar 2026 13:34:30 UTC (436 KB) Access Paper: HTML (experimental) view license Current browse context: cs.CR < prev   |   next > new | recent | 2026-03 Change to browse by: cs References & Citations NASA ADS Google Scholar Semantic Scholar Export BibTeX Citation Bookmark Bibliographic Tools Bibliographic and Citation Tools Bibliographic Explorer Toggle Bibliographic Explorer (What is the Explorer?) Connected Papers Toggle Connected Papers (What is Connected Papers?) Litmaps Toggle Litmaps (What is Litmaps?) scite.ai Toggle scite Smart Citations (What are Smart Citations?) Code, Data, Media Demos Related Papers About arXivLabs Which authors of this paper are endorsers? | Disable MathJax (What is MathJax?)