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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)
Quantum key distribution allows two remote parties, Alice and Bob, to generate a secret key, with privacy guaranteed by quantum mechanics. It has been demonstrated in optical fibers by several groups [1,2,3]. However continuous active adjustment, either of polarization or path length in the setups was necessary. Our group introduced in 1997 an(More)
We introduce a new class of quantum key distribution protocols, tailored to be robust against photon number splitting (PNS) attacks. We study one of these protocols, which differs from the original protocol by Bennett and Brassard (BB84) only in the classical sifting procedure. This protocol is provably better than BB84 against PNS attacks at zero error.
General Trojan horse attacks on quantum key distribution systems are analyzed. We illustrate the power of such attacks with today's technology and conclude that all system must implement active countermeasures. In particular all systems must include an auxiliary detector that monitors any incoming light. We show that such countermeasures can be efficient,(More)
We describe a new quantum key distribution (QKD) protocol that differs from the BB84 only in the classical sifting procedure: instead of revealing the basis, Alice reveals a pair of non-orthogonal states. The new protocol is as robust as BB84 against optimal individual eavesdropping, and is much more robust than BB84 against the most general photon-number(More)
We investigate the performance of separate absorption multiplication InGaAs/InP avalanche photodiodes as single-photon detectors for 1.3- and 1.55-mum wavelengths. First we study afterpulses and choose experimental conditions to limit this effect. Then we compare the InGaAs/InP detector with a germanium avalanche photodiode; the former shows a lower(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)
We present a fibre-optical quantum key distribution system. It works at 1550nm and is based on the plug&play setup. We tested the stability under field conditions using aerial and terrestrial cables and performed a key exchange over 67 km between Geneva and Lausanne. Quantum cryptography or, more exactly, quantum key distribution (QKD) is the most advanced(More)
Quantum key distribution (QKD) is one of the best-known examples of an application of quantum mechanics to cryptography. This article serves as a resource letter, a brief description to the introduction of QKD is provided before surveying the most prominent QKD protocols present in the literature from theoretical initialization by Wiesner to the attempts at(More)
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