How to Securely Shuffle? A survey about Secure Shufflers for privacy-preserving computations
Marc Damie, Florian Hahn, Andreas Peter, Jan Ramon
TL;DR
This survey comprehensively analyzes secure shufflers as practical building blocks for privacy-preserving computations, moving beyond abstract models to compare 26 concrete protocols across six design families. It formalizes core security properties (anonymity, correctness, disruption resistance) and provides a taxonomy of de-anonymization attacks, enabling fair cross-protocol comparisons. The work connects shufflers to a broad set of applications, from private statistics and Shuffle DP to federated learning and secure aggregation, and offers practical guidelines for selecting shufflers based on scalability, message size, and trust assumptions. It also highlights key challenges, including robustness to data poisoning and side-channel risks in TEEs, and outlines future directions for formalizing imperfect shuffles and expanding shuffling-based private computations.
Abstract
Ishai et al. (FOCS'06) introduced secure shuffling as an efficient building block for private data aggregation. Recently, the field of differential privacy has revived interest in secure shufflers by highlighting the privacy amplification they can provide in various computations. Although several works argue for the utility of secure shufflers, they often treat them as black boxes; overlooking the practical vulnerabilities and performance trade-offs of existing implementations. This leaves a central question open: what makes a good secure shuffler? This survey addresses that question by identifying, categorizing, and comparing 26 secure protocols that realize the necessary shuffling functionality. To enable a meaningful comparison, we adapt and unify existing security definitions into a consistent set of properties. We also present an overview of privacy-preserving technologies that rely on secure shufflers, offer practical guidelines for selecting appropriate protocols, and outline promising directions for future work.
