Introduction Quantum key distribution (QKD) [1] enables two remote parties Alice and Bob to share common secure keys which are unknown to a potential eavesdropper. Unconditional security of QKD is based on the fundamental laws of quantum mechanics, but in reality, securities of practical QKD systems could be jeopardized by physical implementations. In discretevariable (DV) QKD system, due to de...

We propose an extension of quantum key distribution based on encoding the key into quNits, i.e. quantum states in an N-dimensional Hilbert space. We estimate both the mutual information between the legitimate parties and the eavesdropper, and the error rate, as a function of the dimension of the Hilbert space. We derive the information gained by an eavesdropper using optimal incoherent attacks ...

Security of quantum key exchange depends on successfully detecting the presence of an eavesdropper. In most cases this is done by comparing the errors introduced by an eavesdropper with the channel error rate. In other words, the communicating parties must tolerate some errors without losing a significant amount of key information. In this paper, we characterize the effects of amplitude damping...

In this paper, we study using Destination Artificial Noise (DAN) besides Source Artificial Noise (SAN) to enhance physical layer secrecy with an outage probability based approach. It is assumed that all nodes in the network (i.e. source, destination and eavesdropper) are equipped with multiple antennas. In addition, the eavesdropper is passive and its channel state and location are unknown at t...

Physical implementations of quantum key distribution (QKD) protocols, like the Bennett-Brassard (BB84), are forced to use attenuated coherent quantum states, because the sources of single photon states are not functional yet for QKD applications. However, when using attenuated coherent states, the relatively high rate of multi-photonic pulses introduces vulnerabilities that can be exploited by ...

With the remarkable progress in microelectronics and low-power semiconductor technologies, Radio Frequency IDentification technology (RFID) has moved from obscurity into mainstream applications, which essentially provides an indispensable foundation to realize ubiquitous computing and machine perception. However, the catching and exclusive characteristics of RFID systems introduce growing secur...

Abstract We study the optimum location of an eavesdropper from a secrecy capacity perspective in multi-terminal networks with power control. We determine the logical location of an eavesdropper (represented by the channel gain from all the transmitters) which a) results in zero secrecy capacity for maximum number of users in the network and b) results in zero secrecy capacity for the bottle-nec...

The crucial issue of quantum communication protocol is its security. A quantum communication scheme must be based on the existing or nearly existing technology, but its security must be guaranteed against an eavesdropper whose technology is limited only by the laws of quantum mechanics. In this paper, we show that all the deterministic and direct two-way quantum communication protocols, sometim...

In this work, a class of information theoretic secrecy problems is addressed where the eavesdropper channel states are completely unknown to the legitimate parties. In particular, MIMO wiretap channel models are considered where the channel of the eavesdropper is arbitrarily varying over time. Assuming that the number of antennas of the eavesdropper is limited, the secrecy rate of the MIMO wire...

In quantum cryptography unconditional security proofs are derived under the assumption that Alice's and Bob's apparata (private spaces) are completely inaccessible by an eavesdropper who, therefore, can only attack the signal systems which are transmitted through the quantum communication channel connecting the two parties. Under this assumption, secret-key rates and security thresholds are der...