Learn More
In this paper, we present the quantum key distribution (QKD) network designed and implemented by the European project SEcure COmmunication based on Quantum Cryptography (SECOQC) (2004–2008), unifying the efforts of 41 research and industrial organizations. The paper summarizes the SECOQC approach to QKD networks with a focus on the trusted repeater(More)
Document history: During the first year of the SECOQC project [1], Philippe Grangier initiated an internal debate regarding the " comparative advantages " of quantum key distribution (QKD). A first written contribution to this debate, by Philippe Grangier, Louis Salvail, Nicolas Gisin and Thierry Debuisschert [2], was then made available to all SECOQC(More)
Reconciliation is an essential part of any secret-key agreement protocol and hence of a Quantum Key Distribution (QKD) protocol, where two legitimate parties are given correlated data and want to agree on a common string in the presence of an adversary, while revealing a minimum amount of information. In this paper, we show that for discrete-variable QKD(More)
A point-to-point quantum key distribution (QKD) system takes advantage of the laws of quantum physics to establish secret keys between two communicating parties. Compared to the classical methods, such as public-key infrastructures, QKD offers unconditional security, which makes it attractive for very high security applications. However, this unprecedent(More)
We propose a method for extracting an errorless secret key in a continuous-variable quantum key distribution protocol, which is based on Gaussian modulation of coherent states and homodyne detection. The crucial feature is an eight-dimensional reconciliation method, relying on the algebraic properties of octonions. By using this coding scheme with an(More)
We report on the design and performance of a point-to-point classical symmetric encryption link with fast key renewal provided by a Continuous Variable Quantum Key Distribution (CVQKD) system. Our system was operational and able to encrypt point-to-point communications during more than six months, from the end of July 2010 until the beginning of February(More)
A Quantum Key Distribution (QKD) network is an infrastructure capable of performing long-distance and high-rate secret key agreement with information-theoretic security. In this paper we study security properties of QKD networks based on trusted repeater nodes. Such networks can already be deployed, based on current technology. We present an example of a(More)
— This paper investigates connections between the theory of quantum noiseless subsystems and the zero-error capacity of quantum channels. In particular, we show that if we have a noiseless subsystem state ρ supported by a projector P , then any quantum state with components in the subspace P ⊥ is adjacent to ρ. This result has some interesting implications(More)