xDup: Privacy-Preserving Deduplication for Humanitarian Organizations using Fuzzy PSI
2026-04-09 • Cryptography and Security
Cryptography and Security
AI summaryⓘ
The authors studied how humanitarian organizations check if people have registered for aid more than once to avoid giving help twice to the same person. They found that sharing data between organizations can put people's privacy at risk. To fix this, the authors created xDup, a new system that helps organizations find duplicates while keeping data safe. xDup works much faster than older methods by using a specialized technique called Fuzzy PSI, making it practical for real-world aid missions.
Humanitarian aidDeduplicationPrivacyCross-organizational cooperationFuzzy PSIHamming SpaceData securityProtocol efficiency
Authors
Tim Rausch, Sylvain Chatel, Wouter Lueks
Abstract
Humanitarian organizations help to ensure people's livelihoods in crisis situations. Typically, multiple organizations operate in the same region. To ensure that the limited budget of these organizations can help as many people as possible, organizations perform cross-organizational deduplication to detect duplicate registrations and ensure recipients receive aid from at most one organization. Current deduplication approaches risk privacy harm to vulnerable aid recipients by sharing their data with other organizations. We analyzed the needs of humanitarian organizations to identify the requirements for privacy-friendly cross-organizational deduplication fit for real-life humanitarian missions. We present xDup, a new practical deduplication system that meets the requirements of humanitarian organizations and is two orders of magnitude faster than current solutions. xDup builds on Fuzzy PSI, and we present otFPSI, a concretely efficient Fuzzy PSI protocol for Hamming Space without input assumptions. We show that it is more efficient than existing Fuzzy PSI protocols.