With the help of a simple quantum key distribution (QKD) scheme, we discuss the relation between BB84-type protocols and two-step-type ones. It is shown that they have the same essence, i.e., information-splitting. More specifically, the similarity between them includes (1) the carrier state is split into two parts which will be sent one by one; (2) the possible states of each quantum part are ...

To enable global scale quantum key distribution (QKD), satellite based systems are the most promising approach. So far, free-space QKD has already been demonstrated on communication channels with attenuation comparable to satellite downlinks, and classical laser communications with satellites and aircrafts is heavily explored. Here, combining both these challenges, we demonstrate an aircraft to...

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We report a telecom-band single-photon detector for highspeed quantum key distribution systems. The single-photon detector is based on a sinusoidally gated InGaAs/InP avalanche photodiode. The gate repetition frequency of the single-photon detector reached 2 GHz. A quantum efficiency of 10.5 % at 1550 nm was obtained with a dark count probability per gate of 6.1×10−7 and an afterpulsing probabi...

This errata contains the mentioned plots where the revised expressions have been applied, such that the replacement for Figure 2 in [1] is shown in Figure 1, and Figure 4 in [1] is shown in Figure 2. We keep the corresponding (b) panels for comparison. We note that the corrections only reinforce the conclusions of our paper, which are that reverse reconciliation is vulnerable to preparation noi...

The problem of'controlling access to multimedia multicasts requires the distribution and maintenance of keying information. The conventional approach to distributing keys is to use a channel independent of the multimedia content. We propose a second approach that involves the use of an data-dependent channel, and can be achieved for multimedia by using data embedding techniques. Using data embe...

Quantum key distribution (QKD) provides a way for distribution of secure key in at least two parties which they initially share. And there are many protocols for providing a secure key i.e. BB84 protocol, SARG04 protocol, E91 protocol and many more. In this paper all the concerned protocols that share a secret key is explained and comparative study of all protocols shown.

Quantum key distribution(QKD) makes it possible for two remotely separated parties do unconditionally secure communications. In principle, the security is guaranteed by the uncertainty principle in quantum mechanics: if any third party watches the key, she must disturbs the quantum bits therefore she has a risk to be detected. However, the security in practice is quite different, since many of ...

Quantum key distribution(QKD) makes it possible for two remotely separated parties do unconditionally secure communications. In principle, the security is guaranteed by the uncertainty principle in quantum mechanics: if any third party watches the key, she must disturbs the quantum bits therefore she has a risk to be detected. However, the security in practice is quite different, since many of ...

We study the number of white balls in a classical Pólya urn model with the additional feature that, at random times, a black ball is added to the urn. The number of draws between these random times are i.i.d. and, under certain moment conditions on the inter-arrival distribution, we characterize the limiting distribution of the (properly scaled) number of white balls as the number of draws goes...