scholarly journals An improved asymptotic key rate bound for a mediated semi-quantum key distribution protocol

2016 ◽  
Vol 16 (9&10) ◽  
pp. 813-834
Author(s):  
Walter O. Krawec

Semi-quantum key distribution (SQKD) protocols allow for the establishment of a secret key between two users Alice and Bob, when one of the two users (typically Bob) is limited or “classical” in nature. Recently it was shown that protocols exists when both parties are limited/classical in nature if they utilize the services of a quantum server. These protocols are called mediated SQKD protocols. This server, however, is untrusted and, in fact, adversarial. In this paper, we reconsider a mediated SQKD protocol and derive a new proof of unconditional security for it. In particular, we derive a new lower bound on its key rate in the asymptotic scenario. Furthermore, we show this new lower bound is an improvement over prior work, thus showing that the protocol in question can tolerate higher rates of error than previously thought.

2021 ◽  
Vol 2056 (1) ◽  
pp. 012011
Author(s):  
Chan Myae Hein ◽  
T F Kamalov

Abstract A new eavesdropping strategy is proposed for the Quantum Key Distribution (QKD) protocol. This scheme represents a new kind of intercept/resend strategy based on Bell’s theorem. Quantum key distribution (QKD) provides the foremost reliable form of secure key exchange, using only the input-output statistics of the devices to realize information-theoretic security. In this paper, we present an improved QKD protocol that can simultaneously distribute the quantum secret key. We are already using the QKD protocol with simulated results matched completely with the theoretical concepts.


2012 ◽  
pp. 13-19
Author(s):  
Riaz Ahmad Qamar ◽  
Mohd Aizaini Maarof ◽  
Subariah Ibrahim

A quantum key distribution protocol(QKD), known as BB84, was developed in 1984 by Charles Bennett and Gilles Brassard. The protocol works in two phases which are quantum state transmission and conventional post processing. In the first phase of BB84, raw key elements are distributed between two legitimate users by sending encoded photons through quantum channel whilst in the second phase, a common secret-key is obtained from correlated raw key elements by exchanging messages through a public channel e.g.; network or internet. The secret-key so obtained is used for cryptography purpose. Reconciliation is a compulsory part of post processing and hence of quantum key distribution protocol. The performance of a reconciliation protocol depends on the generation rate of common secret-key, number of bits disclosed and the error probability in common secrete-key. These characteristics of a protocol can be achieved by using a less interactive reconciliation protocol which can handle a higher initial quantum bit error rate (QBER). In this paper, we use a simple Bose, Chaudhuri, Hocquenghem (BCH) error correction algorithm with simplified syndrome table to achieve an efficient reconciliation protocol which can handle a higher quantum bit error rate and outputs a common key with zero error probability. The proposed protocol efficient in removing errors such that it can remove all errors even if QBER is 60%. Assuming the post processing channel is an authenticated binary symmetric channel (BSC).


2005 ◽  
Vol 94 (4) ◽  
Author(s):  
J.-C. Boileau ◽  
K. Tamaki ◽  
J. Batuwantudawe ◽  
R. Laflamme ◽  
J. M. Renes

2020 ◽  
Vol 10 (1) ◽  
pp. 88-92
Author(s):  
Ali H. Yousif ◽  
Omar S. Mustafa ◽  
Dana F. Abdulqadir ◽  
Farah S. Khoshaba

In this paper, intercept/resend eavesdropper attack over SARG04 quantum key distribution protocol is investigated by bounding the information of an eavesdropper; then, the attack has been analyzed. In 2019, simulation and enhancement of the performance of SARG04 protocol have been done by the same research group in terms of error correction stage using multiparity rather than single parity (Omar, 2019). The probability of detecting the case in the random secret key by eavesdropper is estimated. The results of intercept/resend eavesdropper attack proved that the attack has a significant impact on the operation of the SARG04 protocol in terms of the final key length.


2004 ◽  
Vol 4 (5) ◽  
pp. 325-360
Author(s):  
D. Gottesman ◽  
H.-K. Lo ◽  
N. L\"utkenhaus ◽  
J. Preskill

We prove the security of the Bennett-Brassard (BB84) quantum key distribution protocol in the case where the source and detector are under the limited control of an adversary. Our proof applies when both the source and the detector have small basis-dependent flaws, as is typical in practical implementations of the protocol. We derive a general lower bound on the asymptotic key generation rate for weakly basis-dependent eavesdropping attacks, and also estimate the rate in some special cases: sources that emit weak coherent states with random phases, detectors with basis-dependent efficiency, and misaligned sources and detectors.


2002 ◽  
Vol 13 (10) ◽  
pp. 1387-1392 ◽  
Author(s):  
XIAOYU LI

We provide an asymmetrical quantum key distribution protocol based on the correlations of EPR pairs. It is a variant of the modified Lo–Chau protocol where the EPR pair is not in the state Φ+ but is in one of the four states {Φ±, Ψ±}. The two sides communicating with each other are not equal in the process of establishing the key. A public key system can be built on the protocol. It differs from classical public key system in that there are three keys: the public key, the secret key and the real key.


Entropy ◽  
2019 ◽  
Vol 21 (11) ◽  
pp. 1100 ◽  
Author(s):  
Luyu Huang ◽  
Yichen Zhang ◽  
Ziyang Chen ◽  
Song Yu

A unidimensional continuous-variable quantum key distribution protocol with untrusted detection is proposed, where the two legitimate partners send unidimensional modulated or Gaussian-modulated coherent states to an untrusted third party, i.e., Charlie, to realize the measurement. Compared with the Gaussian-modulated coherent-state protocols, the unidimensional modulated protocols take the advantage of easy modulation, low cost, and only a small number of random numbers required. Security analysis shows that the proposed protocol cannot just defend all detectors side channels, but also achieve great performance under certain conditions. Specifically, three cases are discussed in detail, including using unidimensional modulated coherent states in Alice’s side, in Bob’s side, and in both sides under realistic conditions, respectively. Under the three conditions, we derive the expressions of the secret key rate and give the optimal gain parameters. It is found that the optimal performance of the protocol is achieved by using unidimensional modulated coherent states in both Alice’s and Bob’s side. The resulting protocol shows the potential for long-distance secure communication using the unidimensional quantum key distribution protocol with simple modulation method and untrusted detection under realistic conditions.


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