Quantum cryptography in optical networks and supporting metrology

While the need to provide security has long been a critical driver for the design and architecture of govemment networks, it is also becoming increasingly important to provide secure networking for commercial services over today??s infrastructure. Supporting electronic financial transactions, virtual private networks (VPNs), and virtual local area networks (VLAM) over a shared network are some of the key drivers for security on today??s large service provider and carrier networks. These services today typically depend ou cryptographic algorithms which rely on mathematical or computational complexity for providing security. The conditional security guarantees of these ??classical?? cryptographic methods are predicated on specific assumptions related to future advances in toth mathematical techniques and computation. However, the difficulty in predicting future breakthroughs in mathematical methods and computation may limit the applicability of today??s cryptographic techniques to future security needs.