Biblio
The rate at which a secure key can be generated in a quantum key distribution (QKD) protocol is limited by the channel loss and the quantum bit-error rate (QBER). Increases to the QBER can stem from detector noise, channel noise, or the presence of an eavesdropper, Eve. Eve is capable of obtaining information of the unsecure key by performing an attack on the quantum channel or by listening to all discussion performed via a noiseless public channel. Conventionally a QKD protocol will perform the information reconciliation over the authenticated public channel, revealing the parity bits used to correct for any quantum bit errors. In this invited paper, the possibility of limiting the information revealed to Eve during the information reconciliation is considered. Using a covert communication channel for the transmission of the parity bits, secure key rates are possible at much higher QBERs. This is demonstrated through the simulation of a polarization based QKD system implementing the BB84 protocol, showing significant improvement of the SKRs over the conventional QKD protocols.
Quantum low probability of intercept transmits ciphertext in a way that prevents an eavesdropper possessing the decryption key from recovering the plaintext. It is capable of Gbps communication rates on optical fiber over metropolitan-area distances.
Quantum Key Distribution (QKD) is a technique for sharing encryption keys between two adjacent nodes. It provides unconditional secure communication based on the laws of physics. From the viewpoint of network research, QKD is considered to be a component for providing secure communication in network systems. A QKD network enables each node to exchange encryption keys with arbitrary nodes. However previous research did not focus on the processing speed of the key management method essential for a QKD network. This paper focuses on the key management method assuming a high-speed QKD system for which we clarify the design, propose a high-speed method, and evaluate the throughput. The proposed method consists of four modules: (1) local key manager handling the keys generated by QKD, (2) one-time pad tunnel manager establishing the transparent encryption link, (3) global key manager generating the keys for application communication, and (4) web API providing keys to the application. The proposed method was implemented in software and evaluated by emulating QKD key generation and application key consumption. The evaluation result reveals that it is capable of handling the encryption keys at a speed of 414 Mb/s, 185 Mb/s, 85 Mb/s and 971 Mb/s, for local key manager, one-time pad tunnel manager, global key manager and web API, respectively. These are sufficient for integration with a high-speed QKD system. Furthermore, the method allows the high-speed QKD system consisting of two nodes to expand corresponding to the size of the QKD network without losing the speed advantage.
The security of current key exchange protocols such as Diffie-Hellman key exchange is based on the hardness of number theoretic problems. However, these key exchange protocols are threatened by weak random number generators, advances to CPU power, a new attack from the eavesdropper, and the emergence of a quantum computer. Quantum Key Distribution (QKD) addresses these challenges by using quantum properties to exchange a secret key without the risk of being intercepted. Recent developments on the QKD system resulted in a stable key generation with fewer errors so that the QKD system is rapidly becoming a solid commercial proposition. However, although the security of the QKD system is guaranteed by quantum physics, its careless implementation could make the system vulnerable. In this paper, we proposed the first side-channel attack on plug-and-play QKD system. Through a single electromagnetic trace obtained from the phase modulator on Alice's side, we were able to classify the electromagnetic trace into four classes, which corresponds to the number of bit and basis combination in the BB84 protocol. We concluded that the plug-and-play QKD system is vulnerable to side-channel attack so that the countermeasure must be considered.
We report a an experimental study of device-independent quantum random number generation based on an detection-loophole free Bell test with entangled photons. After considering statistical fluctuations and applying an 80 Gb × 45.6 Mb Toeplitz matrix hashing, we achieve a final random bit rate of 114 bits/s, with a failure probability less than 10-5.
Quantum information exchange computer emulator is presented, which takes into consideration imperfections of real quantum channel such as noise and attenuation resulting in the necessity to increase number of photons in the impulse. The Qt Creator C++ program package provides evaluation of the ability to detect unauthorized access as well as an amount of information intercepted by intruder.
We have presented a unique PT-VCSEL arrangement which experimentally demonstrates the process of optically controlled current confinement. Lessons learned will be transferred to future generations of solitary device which will be optimized with respect to the degree of confinement (depending on the parameters of the PT, in particular the current gain), threshold current and electro-optic efficiency.
Quantum Key Distribution (QKD) is a revolutionary technology which leverages the laws of quantum mechanics to distribute cryptographic keying material between two parties with theoretically unconditional security. Terrestrial QKD systems are limited to distances of \textbackslashtextless;200 km in both optical fiber and line-of-sight free-space configurations due to severe losses during single photon propagation and the curvature of the Earth. Thus, the feasibility of fielding a low Earth orbit (LEO) QKD satellite to overcome this limitation is being explored. Moreover, in August 2016, the Chinese Academy of Sciences successfully launched the world's first QKD satellite. However, many of the practical engineering performance and security tradeoffs associated with space-based QKD are not well understood for global secure key distribution. This paper presents several system-level considerations for modeling and studying space-based QKD architectures and systems. More specifically, this paper explores the behaviors and requirements that researchers must examine to develop a model for studying the effectiveness of QKD between LEO satellites and ground stations.