SBIR-STTR Award

Conventional algorithmic encryption for securing communications in optical WDM netwroks is not readily scalable to high data rates and is vulnerable to off-line cryptanalysis because the algorithm generates a pseudo-random key stream. We propose instead a new concept that avoids these limitations: it is a quantum random digital noise (QRDN) generator capable of generating the identical random bit stream at different geographical locations. In Phase I of this effort, we will design and demonstrate the generation of identical random key streams with two QRDN generators located 100m apart. The generators will consist of matched unbalanced Mach-Zehnder fiber interferometers in open loop operation. As part of Phase I, a concept of operations (CONOPS) will be developed to establish the range of applicability in various optical networks under consideration by the Defense and Telco communities; and a vulnerability analysis will be carried out for various types of attack.

During Phase I, the optical generation of the same key stream at two different locations was experimentally demonstrated. This allows secure encipherment / decipherment of data, which was also demonstrated. The physical basis of Quantum Digital Random Noise (QDRN) is the conversion of optical phase noise into random cryptanalysis. The optical generation of key streams supports arbitrarily high data rates. Optimal digitization of analog signals was identified as the major design issue. QDRN is compatible with single mode fiber, optical amplifiers, and WDM components, but not with electronic regenerators. QDRN is perfectly suited to key distribution; no distribution center or initial shared secret is required. A rudimentary QDRN could also be key manager for conventional cryptography. Phase II will provide for the design, development and testing of a prototype unit. The prototype will be able to transmit secure data through standard single mode fiber using polarization control and will be tested with 1, 10, and 40 km of fiber. The unit will also be tested with optical amplifiers and dense WDM components. It will be delivered and made available for insertion into a testbed optical network to ensure compatibility.