Fiber-Optic Quantum Seal for Safeguards

We report new results on our development of the fiber-optic quantum seal (FOQS) which will provide high-sensitivity tamper detection capabilities at bulk storage facilities to enhance safeguards verification efforts. Long-term verification of critical assets in storage facilities for containment and surveillance must provide material accountancy with continuity of knowledge. As a part of this effort, FOQS will enhance current practices by making use of quantum optical probes to enable fiber-channel integrity checks and sensor data authentication. FOQS consists of an interferometric quantum transceiver which transmits randomly encoded packets of photons over an optical fiber loop used to seal a container. These photon packets return to the receiver to be decoded for amplitude and phase information. Comparisons of the transmit and receive signals allow for the characterization of the channel. If the comparison shows high degree of correlation, channel integrity and authentication are deemed true, while a lack of correlation triggers an intrusion alarm. The key advantage of the FOQS is that the quantum probes are governed by the uncertainty principle which prevents the intruder from attacking the channel without leaving a trace. We present new results obtained in years two and three of this project, including improvements in the experimental system, automated numerical analysis of obtained experimental data, and extended theoretical analysis of the FOQS sensitivity under realistic conditions.