Quantum cryptography and quantum-key distribution with single photons

The overview of the current status of quantum cryptography is given in regard to quantum key distribution (QKD) protocols, implemented both on nonentangled and entangled flying qubits. Two commercial R&D platforms of QKD systems are described (the Clavis II platform by idQuantique implemented on nonentangled photons and the EPR S405 Quelle platform by AIT based on entangled photons) and tested for feasibility of their usage in commercial TELECOM fiber metropolitan networks. The comparison of systems efficiency, stability and resistivity against noise and hacker attacks is given with some suggestion toward system improvement, along with assessment of two models of QKD.

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Cryptanalysis of a Practical Quantum Key Distribution with Polarization-Entangled Photons

Quantum Information and Computation ◽

10.26421/qic5.3-1 ◽

2005 ◽

Vol 5 (3) ◽

pp. 181-186

Author(s):

Th. Beth ◽

J. Muller-Quade ◽

R. Steinwandt

Keyword(s):

Quantum Cryptography ◽

Quantum Key Distribution ◽

Key Distribution ◽

Key Exchange ◽

Authentication Scheme ◽

Entangled Photons ◽

Key Exchange Protocol

Recently, a quantum key exchange protocol has been described\cite{PFLM04}, which served as basis for securing an actual bank transaction by means of quantum cryptography \cite{ZVS04}. The authentication scheme used to this aim has been proposed by Peev et al. \cite{PML04}. Here we show, that this authentication is insecure in the sense that an attacker can provoke a situation where initiator and responder of a key exchange end up with different keys. Moreover, it may happen that an attacker can decrypt a part of the plaintext protected with the derived encryption key.

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Quantum cryptography

Quantum Information ◽

10.1093/oso/9780198527626.003.0006 ◽

2009 ◽

Author(s):

Stephen Barnett

Keyword(s):

Quantum Information ◽

Quantum Cryptography ◽

Quantum Key Distribution ◽

Communication Systems ◽

Information Technologies ◽

Key Distribution ◽

Julius Caesar ◽

Secure Communications ◽

Quantum Communications ◽

History Of

The practical implementation of quantum information technologies requires, for the most part, highly advanced and currently experimental procedures. One exception is quantum cryptography, or quantum key distribution, which has been successfully demonstrated in many laboratories and has reached an advanced level of development. It will probably become the first commercial application of quantum information. In quantum key distribution, Alice and Bob exploit a quantum channel to create a secret shared key comprising a random string of binary digits. This key can then be used to protect a subsequent communication between them. The principal idea is that the secrecy of the key distribution is ensured by the laws of quantum physics. Proving security for practical communication systems is a challenging problem and requires techniques that are beyond the scope of this book. At a fundamental level, however, the ideas are simple and may readily be understood with the knowledge we have already acquired. Quantum cryptography is the latest idea in the long history of secure (and not so secure) communications and, if it is to develop, it will have to compete with existing technologies. For this reason we begin with a brief survey of the history and current state of the art in secure communications before turning to the possibilities offered by quantum communications. The history of cryptography is a long and fascinating one. As a consequence of the success or, more spectacularly, the failure of ciphers, wars have been fought, battles decided, kingdoms won, and heads lost. In the information age, ciphers and cryptosystems have become part of everyday life; we use them to protect our computers, to shop over the Internet, and to access our money via an ATM (automated teller machine). One of the oldest and simplest of all ciphers is the transposition or Caesarean cipher (attributed to Julius Caesar), in which the letters are shifted by a known (and secret) number of places in the alphabet. If the shift is 1, for example, then A is enciphered as B, B→C, · · ·, Y→Z, Z→A. A shift of five places leads us to make the replacements A→F, B→G, · · ·, Y→D, Z→E.

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Chaotic Quantum Key Distribution

Cryptography ◽

10.3390/cryptography4030024 ◽

2020 ◽

Vol 4 (3) ◽

pp. 24

Author(s):

Noah Cowper ◽

Harry Shaw ◽

David Thayer

Keyword(s):

Quantum Computing ◽

Quantum Key Distribution ◽

Single Photon ◽

Photon Emission ◽

Key Distribution ◽

Maximum Amount ◽

Single Photons ◽

Single Photon Emission ◽

Amount Of Information ◽

Communication Scheme

The ability to send information securely is a vital aspect of today’s society, and with the developments in quantum computing, new ways to communicate have to be researched. We explored a novel application of quantum key distribution (QKD) and synchronized chaos which was utilized to mask a transmitted message. This communication scheme is not hampered by the ability to send single photons and consequently is not vulnerable to number splitting attacks like other QKD schemes that rely on single photon emission. This was shown by an eavesdropper gaining a maximum amount of information on the key during the first setup and listening to the key reconciliation to gain more information. We proved that there is a maximum amount of information an eavesdropper can gain during the communication, and this is insufficient to decode the message.

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Performance limits for single-photons, correlated-photons, and entangled photons for quantum key distribution over fiber optics network topologies

10.1117/12.2087027 ◽

2015 ◽

Author(s):

Eric Donkor ◽

Fahad Althowibi ◽

Ryan Williams

Keyword(s):

Fiber Optics ◽

Quantum Key Distribution ◽

Key Distribution ◽

Single Photons ◽

Entangled Photons ◽

Performance Limits ◽

Network Topologies

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Quantum key distribution security constraints caused by controlled quality of dark channel for non-entangled and entangled photon quantum cryptography setups

Optical and Quantum Electronics ◽

10.1007/s11082-016-0624-9 ◽

2016 ◽

Vol 48 (7) ◽

Cited By ~ 1

Author(s):

Monika Jacak ◽

Damian Melniczuk ◽

Janusz Jacak ◽

Andrzej Janutka ◽

Ireneusz Jóźwiak ◽

...

Keyword(s):

Quantum Cryptography ◽

Quantum Key Distribution ◽

Key Distribution ◽

Dark Channel

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A practical trojan horse for Bell-inequality-based quantum cryptography

Quantum Information and Computation ◽

10.26421/qic2.6-2 ◽

2002 ◽

Vol 2 (6) ◽

pp. 434-442

Author(s):

J. Larsson

Keyword(s):

Quantum Cryptography ◽

Quantum Channel ◽

Quantum Key Distribution ◽

Bell Inequality ◽

Trojan Horse ◽

Unconditional Security ◽

Single Photons ◽

Secret Key ◽

Photon Polarization ◽

At Will

Quantum Cryptography, or more accurately, Quantum Key Distribution (QKD) is based on using an unconditionally secure ``quantum channel'' to share a secret key among two users. A manufacturer of QKD devices could, intentionally or not, use a (semi-)classical channel instead of the quantum channel, which would remove the supposedly unconditional security. One example is the BB84 protocol, where the quantum channel can be implemented in polarization of single photons. Here, use of several photons instead of one to encode each bit of the key provides a similar but insecure system. For protocols based on violation of a Bell inequality (e.g., the Ekert protocol) the situation is somewhat different. While the possibility is mentioned by some authors, it is generally thought that an implementation of a (semi-)classical channel will differ significantly from that of a quantum channel. Here, a counterexample will be given using an identical physical setup as is used in photon-polarization Ekert QKD. Since the physical implementation is identical, a manufacturer may include this modification as a Trojan Horse in manufactured systems, to be activated at will by an eavesdropper. Thus, the old truth of cryptography still holds: you have to trust the manufacturer of your cryptographic device. Even when you do violate the Bell inequality.

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Experimental investigation of high-dimensional quantum key distribution protocols with twisted photons

Quantum ◽

10.22331/q-2018-12-04-111 ◽

2018 ◽

Vol 2 ◽

pp. 111 ◽

Cited By ~ 23

Author(s):

Frédéric Bouchard ◽

Khabat Heshami ◽

Duncan England ◽

Robert Fickler ◽

Robert W. Boyd ◽

...

Keyword(s):

Quantum Key Distribution ◽

Key Distribution ◽

High Dimensional ◽

Multiple Quantum ◽

Single Photons ◽

Experimental Conditions ◽

Differential Phase Shift ◽

Secure Information ◽

Experimental Apparatus ◽

First Time

Quantum key distribution is on the verge of real world applications, where perfectly secure information can be distributed among multiple parties. Several quantum cryptographic protocols have been theoretically proposed and independently realized in different experimental conditions. Here, we develop an experimental platform based on high-dimensional orbital angular momentum states of single photons that enables implementation of multiple quantum key distribution protocols with a single experimental apparatus. Our versatile approach allows us to experimentally survey different classes of quantum key distribution techniques, such as the 1984 Bennett & Brassard (BB84), tomographic protocols including the six-state and the Singapore protocol, and to investigate, for the first time, a recently introduced differential phase shift (Chau15) protocol using twisted photons. This enables us to experimentally compare the performance of these techniques and discuss their benefits and deficiencies in terms of noise tolerance in different dimensions.

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