Abstract

The Quantum Tokens Initiative is a project to explore Quantum Tokens for Message Authentication Codes (TMAC). TMACs enhance classical message authentication by employing single-use quantum tokens—stateful quantum objects—that allow precisely one valid signing operation each. This uncloneable characteristic ensures that even if a signing token is intercepted, malicious parties cannot replicate it to generate unauthorized signatures.

Building on the framework presented in Noise-Tolerant Quantum Tokens for MAC by Behera, Sattath, and Shinar, our aim is to develop and deploy a proof-of-concept system demonstrating how such tokens can underpin a private quantum money scheme. Unlike standard quantum money protocols, this approach avoids the need for long-term quantum memory at the cost of trusting the bank to minting and verifying tokens when tokens are received or spent.

Through this initiative, we seek to bridge theoretical advances in quantum cryptography with the practical challenges and opportunities of today’s quantum infrastructure.

Deliverables

Our deliverables are as following:

1. Deploy a live (non-simulated) Private Quantum Money protocol using TMAC.
2. Produce a report of the stack used and potential improvement to deploy application on the quantum internet.

Requirements

1. Existing hardware: The protocol must run on existing production-ready hardware (for example: no long-term quantum memory).
2. Prepare-and-measure: The protocol must be preparation and measurement of BB84 state.
3. QKD-based network: The communication steps of the protocol must run existing QKD-based network infrastructure.

Milestones

1. Implementation Feasibility
• Investigate possibilities for constructing and distributing quantum tokens in realistic operating environments.
• Study how to adapt the theoretical framework—particularly the noise tolerance features—to existing quantum hardware and software stacks.
2. Collaboration and Deployment
• Engage with quantum hardware vendors, cloud providers, and operators to understand the practical limits (e.g., memory coherence times, gate fidelity, system integration).
• Determine how best to integrate these tokens into real-world quantum networks or remote lab setups.
3. Demonstration and Next Steps
• Build a prototype demonstrating token creation, usage, and verification.
• Evaluate its performance under varying noise and memory conditions to gauge real-world viability.

References

• Noise-Tolerant Quantum Tokens for MAC [BSS21] https://arxiv.org/pdf/2105.05016
• Optimal counterfeiting attacks and generalizations for Wiesner’s quantum money [MVW12] https://arxiv.org/pdf/1202.4010
• Quantum Money with Classical Verification [Gavinsky12] https://arxiv.org/pdf/1109.0372
• Unforgeable Noise-Tolerant Quantum Tokens [PYJ+11] https://arxiv.org/pdf/1112.5456