Simulated Multiparty Quantum Digital Signature in Cyberspace Operations

Research on new cryptographic mechanisms to protect against the threat of quantum computers has attracted great interest, especially due to the impact that this new technologies will have on the security of cyber-operations. After the widely tested and implemented Quantum Key Distribution (QKD) protocol for the generation of symmetric encryption keys, other protocols are being explored, such as Quantum Digital Signatures (QDS). Their classic analogues based on asymmetric cryptography will be vulnerable to Shor's quantum algorithm. Given the applicability that QDS could have in multi-domain operations, in this work we have analyzed and implemented a quantum-safe QDS protocol in a simulated environment provided with real QKD-generated keys. First, we recreated a basic three-user scenario composed of one signer and two verifiers, and later generalized by increasing the number of users by simulating a scheme with one signer and multiple verifiers. Our simulation also allows one participating user to be malicious, thus playing with the number of attack vectors and the breaking points of the forwarding chain. In addition, a use case is presented in which the QDS protocol is performed to confirm orders along the command chain, demonstrating its applicability. This paper was originally presented at the NATO Science and Technology Organization Symposium (ICMCIS) organized by the Information Systems Technology (IST) Panel, IST-200RSY — the ICMCIS, held in Skopje, North Macedonia, 16–17 May 2023.