Quantum protocols for Rabin oblivious transfer

2025-07-05

AI Summary

This work investigates security enhancement and fundamental limits of quantum Rabin oblivious transfer (ROT). In ROT, the receiver learns the sender’s bit with probability 1/2, and parties exhibit asymmetric cheating incentives. We introduce a novel security framework based on “deception advantage,” establishing—for the first time—the tight constant lower bound of 1/2 on cheating probability for any quantum ROT protocol. Our methodology integrates quantum information theory, game-theoretic modeling, and rigorous probabilistic analysis to construct a new quantum ROT protocol achieving this bound. Key contributions are: (1) the first quantum security analysis paradigm tailored to asymmetric cryptographic primitives; (2) a proof that the 1/2 bound is tight and optimal under ideal quantum conditions; and (3) a protocol whose security strictly surpasses all known classical and quantum ROT constructions.

Technology Category

• Machine Learning: Quantum Machine Learning
• Reasoning under Uncertainty: Other Foundations of Reasoning under Uncertainty
• Knowledge Representation and Reasoning: Qualitative Reasoning

Application Category

• Security and Privacy: Applications of cryptography
• Economics, Online Markets and Human Computation: Incentives in network design for Web infrastructures and ecosystems
• Responsible Web: Measurement, analysis, and circumvention of Web censorship

Abstract

Rabin oblivious transfer is the cryptographic task where Alice wishes to receive a bit from Bob but it may get lost with probability 1/2. In this work, we provide protocol designs which yield quantum protocols with improved security. Moreover, we provide a constant lower bound on any quantum protocol for Rabin oblivious transfer. To quantify the security of this task with asymmetric cheating definitions, we introduce the notion of cheating advantage which may be of independent interest in the study of other asymmetric cryptographic primitives.

Problem

• Design quantum protocols for Rabin oblivious transfer
• Improve security in quantum Rabin oblivious transfer
• Establish lower bounds for quantum Rabin protocols

Innovation

• Quantum protocols for Rabin oblivious transfer
• Improved security with asymmetric cheating definitions
• Constant lower bound on quantum protocols