The ability to know and verifiably demonstrate the origins of messages can often be as important as encrypting the message itself. Here we present an experimental demonstration of an unconditionally secure digital signature (USS) protocol implemented for the first time, to the best of our knowledge, on a fully connected quantum network without trusted nodes. Our USS protocol is secure against forging, repudiation and messages are transferrable. We show the feasibility of unconditionally secure signatures using only bi-partite entangled states distributed throughout the network and experimentally evaluate the performance of the protocol in real world scenarios with varying message lengths.
@article{arxiv.2202.04641,
title = {Unconditionally secure digital signatures implemented in an 8-user quantum network},
author = {Yoann Pelet and Ittoop Vergheese Puthoor and Natarajan Venkatachalam and Sören Wengerowsky and Martin Lončarić and Sebastian Philipp Neumann and Bo Liu and Željko Samec and Mario Stipčević and Rupert Ursin and Erika Andersson and John G. Rarity and Djeylan Aktas and Siddarth Koduru Joshi},
journal= {arXiv preprint arXiv:2202.04641},
year = {2022}
}