Studies on the Quantum Private Query primitive in the DeviceIndependent paradigm

11 March 2025

Title: Studies on the Quantum Private Query primitive in the DeviceIndependent paradigm

Speaker: Dr. Jyotirmoy Basak, Indian Statistical Institute, Kolkata

Abstract of Talk: This talk will primarily focus on the Quantum Private Query (QPQ) primitive within the Device-Independent (DI) paradigm, where the challenges of preserving both user and database privacy will be addressed without assuming the trustworthiness of the involved devices. It has been shown that existing cryptographic primitives, such as Symmetric Private Information Retrieval (SPIR) and 1-out-of-N Oblivious Transfer (OT), do not provide unconditional security with a single server in both classical and quantum domains. To overcome this limitation, the QPQ primitive has been designed to ensure that the client obtains only probabilistic knowledge about unintended data bits while the server abstains from cheating.

In this talk, the contributions of the speaker to the QPQ primitive (mostly within the DI framework) will be presented. These include the introduction of a novel DI-QPQ scheme utilising EPR pairs, addressing the limitations of a semi-DIQPQ proposal and developing its fully DI version, as well as overcoming the limitations of existing multi-user QPQ schemes through the proposal of a semi-DI multi-user QPQ scheme. Additionally, the formal security assessment for all DI-QPQ proposals will be discussed, and the related upper bounds on cheating probabilities will also be mentioned to ensure the robustness of DI-QPQ implementations. Finally, some open problems in this direction will be discussed, along with the future research interests of the speaker.

Profile of Speaker: Jyotirmoy holds a Bachelor's degree in Computer Science from West Bengal University of Technology and a Master's and PhD in Computer Science from the Indian Statistical Institute, Kolkata. His primary research interest encompasses various aspects of Quantum Cryptography. Additionally, he has a keen interest in exploring different facets of Classical and Quantum Complexity Theory, Classical Cryptography and other topics in Theoretical Computer Science.