We consider the problem of secure key distribution among n trustful agents: the goal is to distribute an identical random bit-string among the n agents over a noisy channel such that eavesdroppers learn little about it. We study the general situation where the only resources required are secure bipartite key distribution and authenticated classical communication. Accordingly, multipartite quant...

Quantum key distribution is among the foremost applications of quantum mechanics, both in terms of fundamental physics and as a technology on the brink of commercial deployment. Starting from principal schemes and initial proofs of unconditional security for perfect systems, much effort has gone into providing secure schemes which can cope with numerous experimental imperfections unavoidable in...

E.O. Kiktenko, 2, 3 N.O. Pozhar, 3 A.V. Duplinskiy, 4 A.A. Kanapin, 5 A.S. Sokolov, S.S. Vorobey, A.V. Miller, V.E. Ustimchik, M.N. Anufriev, 3 A.S. Trushechkin, R.R. Yunusov, V.L. Kurochkin, Y.V. Kurochkin, and A.K. Fedorov ∗ Russian Quantum Center, Skolkovo, Moscow 143025, Russia Steklov Mathematical Institute of Russian Academy of Sciences, Moscow 119991, Russia Bauman Moscow State Technical...

We propose a proof of the security of EPR-based quantum key distribution against enemies with unlimited computational power. The proof holds for a protocol using interactive error-reconciliation scheme. We assume in this paper that the legitimate parties receive a given number of single photon signals and that their measurement devices are perfect.

Based on the controlled order rearrange encryption (CORE) for quantum key distribution using EPR pairs[Fu.G.Deng and G.L.Long Phys.Rev.A68 (2003) 042315], we propose the generalized controlled order rearrangement encryption (GCORE) protocols of N qubits and N qutrits, concretely display them in the cases using 3-qubit, 2-qutrit maximally entangled basis states. We further indicate that our prot...

Catch 22 of cryptography -"Before two parties can communicate in secret, they must first communicate in secret". The weakness of classical cryptographic communication systems is that secret communication can only take place after a key is communicated in secret over a totally secure communication channel. Here comes quantum key distribution which takes advantage of certain phenomena that occur ...

This paper compares the popular quantum key distribution (QKD) protocol BB84 with the more recent Kak’s three-stage protocol and the latter is shown to be more secure. A theoretical representation of an authentication-aided version of Kak’s threestage protocol is provided that makes it possible to deal with man-in-the-middle attack.

The progress in silicon planar device technologies has led single-photon avalanche diodes (SPAD) to emerge from the laboratory research phase and be commercially available from various manufactures. QKD systems can already exploit the available planar Si-SPAD devices, but they set strong demand for improved features and performance. A response can be given by new developments in a dedicated sil...

This paper introduces a variation on Kak’s three-stage quanutm key distribution protocol which allows for defence against the man in the middle attack. In addition, we introduce a new protocol, which also offers similar resiliance against such an attack.

Terrestrial QKD channels can connect two links with a maximum distance of few hundred kilometres. In the case of fibre links, this is due to the signal attenuation in the fibre; in the case of free-space link the losses are due to atmospheric turbulence and absorption. Free-space optical terminals exploiting satellite-based relays are the only resource that can enable global scale quantum key d...