Multimodal Privacy-Preserving Entity Resolution with Fully Homomorphic Encryption
Susim Roy, Nalini Ratha
TL;DR
The paper tackles identity reconciliation in high-compliance domains under strict privacy constraints by proposing a multimodal framework that operates entirely in encrypted space using Fully Homomorphic Encryption (FHE). It combines biometric and biographic information via trainable BMMLP/BGMLP modules, trained with CLIP-based encoders, and performs encrypted enrollment and verification with the RNS-CKKS scheme, leveraging both feature-level and score-level fusion. The key contributions include a synthetic, scalable multimodal dataset, a complete encrypted pipeline for enrollment and verification, and empirical evidence that encrypted matching preserves accuracy while enabling privacy guarantees, along with notable latency benefits from parallelization. This approach offers a practical path toward secure, scalable identity resolution for institutions like DMVs and banks, enabling regulatory compliance without exposing sensitive Personal Identifiable Information during the matching lifecycle.
Abstract
The canonical challenge of entity resolution within high-compliance sectors, where secure identity reconciliation is frequently confounded by significant data heterogeneity, including syntactic variations in personal identifiers, is a longstanding and complex problem. To this end, we introduce a novel multimodal framework operating with the voluminous data sets typical of government and financial institutions. Specifically, our methodology is designed to address the tripartite challenge of data volume, matching fidelity, and privacy. Consequently, the underlying plaintext of personally identifiable information remains computationally inaccessible throughout the matching lifecycle, empowering institutions to rigorously satisfy stringent regulatory mandates with cryptographic assurances of client confidentiality while achieving a demonstrably low equal error rate and maintaining computational tractability at scale.
