Speaker: Stanislav Kruglik，Nanyang Technological University

Title: Querying Twice: Ensuring Correct File Retrieval in Private Information Retrieval Protocols

Language: English

Time & Venue: 2024.12.06 15:00-16:00 Tencent Meeting(Voov meeting)：651-701-018

Abstract: In modern data storage systems, it is essential not only to store data securely but also to retrieve it efficiently while satisfying specific requirements. One such requirement is maintaining the privacy of the queried index. Private Information Retrieval (PIR) is a cryptographic technique that enables clients to retrieve records from a database hosted by one or more untrusted servers without revealing which record was accessed. While many existing PIR protocols assume that servers are honest but curious, this talk focuses on scenarios where dishonest servers intentionally provide incorrect responses to mislead clients. We introduce a unified classification of protocols designed to address such adversarial behavior and demonstrate a protocol that checks the correctness of file retrieval with a bounded error probability. Additionally, we propose a method to reduce the extracommunication cost by relaxing the information-theoretic security guarantees.