Information-theoretically secure quantum timestamping with one-time universal hashing

TL;DR

This paper introduces a quantum timestamping protocol that offers information-theoretic security and high efficiency, suitable for long documents and practical deployment, advancing quantum cryptography.

Contribution

It presents a novel quantum timestamping protocol based on one-time universal hashing with quantum keys, achieving security without computational assumptions.

Findings

Generation rate exceeds 100 timestamps per second over intercity distances

Protocol only requires weak coherent states for practicality

Achieves both information-theoretic security and efficiency

Abstract

Accurate and tamper-resistant timestamps are essential for applications demanding verifiable chronological ordering, such as legal documentation and digital intellectual property protection. Classical timestamp protocols rely on computational assumptions for security, rendering them vulnerable to quantum attacks, which is a critical limitation given the rapid progress in quantum computing. To address this, we propose an information-theoretically secure quantum timestamping protocol based on one-time universal hashing with quantum keys. Our protocol simultaneously achieves information-theoretic security and high efficiency, enabling secure timestamping for arbitrarily long documents. Simulations demonstrate a generation rate exceeding 100 timestamps per second over intercity distances. In addition, our protocol only requires weak coherent states, making it practical for large-scale deployment. This work advances the field of quantum timestamping and contributes to the broader development of quantum cryptography and the future quantum internet.