We demonstrate high-speed (1 Gbps) data encryption and optical transmission using 'quantum noise diffusion cryptography'. M-ary amplitude modulating scheme over 100 levels will enhance the quantum noise effect on encrypted data and prevents eavesdropping. (2 pages)
We demonstrate high-speed (0.25Gbps) data encryption over 50km of telecom fiber using coherent states of light. For the parameter values used in the experiment, the demonstration is secure against individual ciphertext-only eavesdropping attacks near the transmitter with ideal detection equipment. While other quantum cryptographic schemes require the use of fragile quantum states and ultra-sensitive detection equipment, our protocol is loss tolerant, uses off-the-shelf components, and is optically amplifiable.
We will describe keyed communication in quantum noise (KCQ) and how it can be used for either data encryption or key generation. Specifically, we will focus on the AlphaEta protocol for data encryption where the role of quantum noise will be discussed. Additionally, the potential of using classical noise to enhance security via deliberate signal randomization (DSR) will be investigated. We will also investigate the effect of unwanted impairments, such as nonlinearities in a wavelength-division-multiplexed fiber transmission system, and how they affect the ultimate allowable propagation distance. Our simulations and experiments suggest that AlphaEta-protocol based physical-layer encryption is compatible with long-haul optical transmission systems operating at Gb/s data rates.
We report on a new physical layer optical encryption approach based on quantum noise limited optical signals and M-ary optical phase shift keying that operates at high data rates. In contrast to established encryption methods that rely solely on deterministic algorithms, this system utilizes quantum noise to realize a randomized cipher. Keyed M-ary optical phase modulation is used to encrypt quantum-noise limited mesoscopic signals (50k photons/bit) that are compatible with current directions in optical networking: the physically encrypted signals may be optically amplified, routed through optical switches, and can propagate over long distances approaching 1000 km. We describe the approach in detail and report on results of experiments in which these encrypted signals were transmitted over an 850 km network at 622 Mb/s. Bit-error rate measurements were performed under varying network conditions. Our paper concludes with the engineering challenges for extending this approach to 2.5 Gb/s and beyond and how these are being addressed
We describe an emerging method of encryption suitable for high-speed optical communication networks. This encryption protocol combines traditional electronic cryptographic algorithms with the physical effect of optical noise of quantum origin to create a highly secure method of secret communications. The resulting optical signal is compatible with today's high speed fiber optic infrastructure including optical amplification and add/drop multiplexing. Systems implementing this protocol can be constructed with common commercially available components. We describe experimental results obtained with a 2.5 Gb/s system. The encrypted signal is shown to travel error-free through >500 km of optical fiber. Simulations show that reaches and data rates consistent with modern long haul optical networks are attainable.
We report the first on-line high-speed and large-capacity secure optical communication system. This was realized by combining a quadrature amplitude modulation/quantum noise stream cipher technology where a coherent multi-level optical signal is hidden in quantum noise and a quantum key distribution technology where secure key delivery is realized with an extremely weak laser light comparable to a single photon. In our security analysis, we adopt a realistic assumption, namely, that an adversary does not have a lossless fiber. To show the advantage of this scheme, we performed a 128 QAM, 70-Gbit/s single-channel transmission over 100 km with a spectral efficiency of as high as 10.3 bits/s/Hz. This is the fastest data rate and highest spectral efficiency yet achieved in quantum cryptography with a realistic assumption.
To guarantee a security of Cloud Computing System is urgent problem. Although there are several threats in a security problem, the most serious problem is cyber attack against an optical fiber transmission among data centers. In such a network, an encryption scheme on Layer 1(physical layer) with an ultimately strong security, a small delay, and a very high speed should be employed, because a basic optical link is operated at 10 Gbit/sec/wavelength. We have developed a quantum noise randomied stream cipher so called Yuen- 2000 encryption scheme (Y-00) during a decade. This type of cipher is a completely new type random cipher in which ciphertext for a legitimate receiver and eavesdropper are different. This is a condition to break the Shannon limit in theory of cryptography. In addition, this scheme has a good balance on a security, a speed and a cost performance. To realize such an encryption, several modulation methods are candidates such as phase-modulation, intensity-modulation, quadrature amplitude modulation, and so on. Northwestern university group demonstrated a phase modulation system (α=η) in 2003. In 2005, we reported a demonstration of 1 Gbit/sec system based on intensity modulation scheme(ISK-Y00), and gave a design method for quadratic amplitude modulation (QAM-Y00) in 2005 and 2010. An intensity modulation scheme promises a real application to a secure fiber communication of current data centers. This paper presents a progress in quantum noise randomized stream cipher based on ISK-Y00, integrating our theoretical and experimental achievements in the past and recent 100 Gbit/sec(10Gbit/sec × 10 wavelengths) experiment.