Resend Attack Research Articles

Use of Nash equilibrium in finding game theoretic robust security bound on quantum bit error rate

Nash equilibrium is employed to find a game theoretic robust security bound on quantum bit error rate (QBER) for DL04 protocol which is a scheme for quantum secure direct communication that has been experimentally realized recently. The receiver, sender and eavesdropper (Eve) are considered to be quantum players (players having the capability to perform quantum operations). Specifically, Eve is considered to have the capability of performing quantum attacks (e.g., Wójcik’s original attack, Wójcik’s symmetrized attack and Pavičić attack) and classical intercept and resend attack. Game theoretic analysis of the security of DL04 protocol in the above scenario is performed by considering several game scenarios. The analysis revealed the absence of a Pareto optimal Nash equilibrium point within these game scenarios. Consequently, mixed strategy Nash equilibrium points are identified and employed to establish both upper and lower bounds for QBER. Further, the vulnerability of the DL04 protocol to Pavičić attack in the message mode is established. In addition, it is observed that the quantum attacks performed by Eve are more powerful than the classical attack, as the QBER value and the probability of detecting Eve’s presence are found to be lower in quantum attacks compared to classical ones.

Quantum direct communication protocol using recurrence in k -cycle quantum walks

The ability of quantum walks to evolve in a superposition of distinct quantum states has been used as a resource in quantum communication protocols. Under certain settings, the $k$-cycle discrete-time quantum walks\,(DTQW) are known to recur to its initial state after every $t_r$ steps. We first present a scheme to optically realize any $k$-cycle DTQW using $J$-plate, orbital angular momentum\,(OAM) sorters, optical switch, and optical delay line. This entangles the polarization and OAM degrees of freedom\,(DoF) of a single photon. Making use of this recurrence phenomena of $k$-cycle DTQW and the entanglement generated during the evolution, we present a new quantum direct communication protocol. The recurrence and entanglement in $k$-cycle walk are effectively used to retrieve and secure the information, respectively, in the proposed protocol. We investigate the security of the protocol against intercept and resend attack. We also quantify the effect of amplitude damping and depolarizing noises on recurrence and mutual information between polarization and OAM DoF of a single photon.

Multi-party semi-quantum key distribution protocol based on hyperentangled Bell states

Semi-quantum key distribution allows generating a raw key between two communication participants, in which the sender is a quantum participant and the receiver is a classical participant. This article presents an original semi-quantum key distribution protocol based on hyperentangled Bell states. The hyperentangled Bell states can be entangled simultaneously in polarization and spatial degrees of freedom, enhancing channel capacity. According to the characteristics of hyperentangled Bell states, the proposed protocol is more efficient than the protocol based on Bell states. Moreover, the measure–resend attack, the intercept–resend attack, and the entangle–measure attack are analyzed in detail. The security analysis demonstrates that the proposed protocol is secure. In addition, a multi-party semi-quantum key distribution scheme based on hyperentangled Bell states is proposed, which can realize key distribution between one quantum participant and multiple classical participants.

BB84 with several intercepts and resend attacks using partially non-orthogonal basis states through a depolarising channel

The paper presents the partially non-orthogonal basis states effect in presence of several intercept and resend attacks through a depolarising channel. The quantum error and the mutual information are computed for arbitrary angles of the non-orthogonal basis states and the depolarising channel parameter. It is found that the information security depends strongly on the non-orthogonal basis states angle, the depolarising channel parameter, the intercepts and resend attack probability and the eavesdropper number. Besides, it is found that for any eavesdropper's number and basis states angle, the protocol is more secure if the depolarisation parameter is lower than a threshold value and the maximum value of the quantum error decreases by increasing the depolarising parameter and/or the eavesdropper's number. While for the depolarisation parameter above the threshold value the protocol is not secured independently of any values of the non-orthogonal basis states angle and/or the eavesdroppers' number.

Quantum direct communication protocols using discrete-time quantum walk

The unique features of quantum walk, such as the possibility of the walker to be in superposition ofthe position space and get entangled with the position space, provides inherent advantages that canbe captured to design highly secure quantum communication protocols. Here we propose two quan-tum direct communication protocols, a Quantum Secure Direct Communication (QSDC) protocoland a Controlled Quantum Dialogue (CQD) protocol using discrete-time quantum walk on a cycle.The proposed protocols are unconditionally secure against various attacks such as the intercept-resend attack, the denial of service attack, and the man-in-the-middle attack. Additionally, theproposed CQD protocol is shown to be unconditionally secure against an untrusted service providerand both the protocols are shown more secure against the intercept resend attack as compared tothe qubit based LM05/DL04 protocol.

Quantum Key Distillation Using Binary Frames

We introduce a new integral method for Quantum Key Distribution to perform sifting, reconciliation and amplification processes to establish a cryptographic key through the use of binary matrices called frames which are capable to increase quadratically the secret key rate. Since the eavesdropper has no control on Bob’s double matching detection events, our protocol is not vulnerable to the Intercept and Resend (IR) attack nor the Photon Number Splitting (PNS) attack. The method can be implemented with the usual optical Bennett–Brassard ( B B 84 ) equipment allowing strong pulses in the quantum regime.

Controller-independent quantum bidirectional communication using non-maximally entangled states

In the recent past, Mohapatra and Balakrishnan (Quantum Inf Process 16:147, 2017) proposed a controller-independent bidirectional quantum direct communication protocol using Bell states. In this work, we show the possibility of the achieving same protocol with non-maximally entangled states without compromising on the security and the efficiency of the protocol. We exploit the degree of entanglement as an additional security parameter. By doing so, the eavesdropper always gets detected in the initial stages of the protocol in the case of an intercept and resend attack. On the other hand, there is only 25% chance that the eavesdropper goes undetected in the initial stages of the protocol proposed by Mohapatra and Balakrishnan. Thus, the proposed protocol can be implemented with the viable physical resources.

Analyses and improvement of a broadcasting multiple blind signature scheme based on quantum GHZ entanglement

A broadcasting multiple blind signature scheme based on quantum GHZ entanglement has been presented recently. It is said that the scheme’s unconditional security is guaranteed by adopting quantum key preparation, quantum encryption algorithm and quantum entanglement. In this paper, we prove that each signatory can get the signed message just by an intercept–resend attack. Then, we show there still exist some participant attacks and external attacks. Specifically, we verify the message sender Alice can impersonate each signatory to sign the message at will, and so is the signature collector Charlie. Also, we demonstrate that the receiver Bob can forge the signature successfully, and with respect to the external attacks, the eavesdropper Eve can modify the signature at random. Besides, we discover Eve can change the signed message at random, and Eve can impersonate Alice as the message sender without being discovered. In particular, we propose an improved scheme based on the original one and show that it is secure against not only the attacks mentioned above but also some collusion attacks.

Cryptanalysis on a scheme to share information via employing a discrete algorithm to quantum states

Recently, Yang and Hwang [Int. J. Theor. Phys. 53, 224 (2014)] demonstrated that the scheme to share information via employing discrete algorithm to quantum states presented by Kang and Fang [Commun. Theor. Phys. 55, 239 (2011)] suffers from a major vulnerability allowing an eavesdropper to perform a measurement and resend attack. By introducing an additional checking state framework, the authors have proposed an improved protocol to overcome this weakness. This work calls into question the invoked vulnerability in order to clarify a misinterpretation in the same protocol stages also introduce a possible leakage information strategy, known as a faked state attack, despite the proposed improvement, which means that the same security problem may persist. Finally, an upgrading technic was introduced in order to enhance the security transmission.

Engineering trade studies for a quantum key distribution system over a 30 km free-space maritime channel.

Here, we present the engineering trade studies of a free-space optical communication system operating over a 30 km maritime channel for the months of January and July. The system under study follows the BB84 protocol with the following assumptions: a weak coherent source is used, Eve is performing the intercept resend attack and photon number splitting attack, prior knowledge of Eve's location is known, and Eve is allowed to know a small percentage of the final key. In this system, we examine the effect of changing several parameters in the following areas: the implementation of the BB84 protocol over the public channel, the technology in the receiver, and our assumptions about Eve. For each parameter, we examine how different values impact the secure key rate for a constant brightness. Additionally, we will optimize the brightness of the source for each parameter to study the improvement in the secure key rate.

Cryptanalysis and improvement of quantum broadcast communication and authentication protocol with a quantum one-time pad**Project supported by the National Natural Science Foundation of China (Grant Nos. 61502101 and 61170321), the Natural Science Foundation of Jiangsu Province, China (Grant No. BK20140651), the Research Fund for the Doctoral Program of Higher Education, China (Grant No. 20110092110024), and the Project Funded by PAPD

The security of quantum broadcast communication (QBC) and authentication protocol based on Greenberger–Horne–Zeilinger (GHZ) state and quantum one-time pad is analyzed. It is shown that there are some security issues in this protocol. Firstly, an external eavesdropper can take the intercept–measure–resend attack strategy to eavesdrop on 0.369 bit of every bit of the identity string of each receiver without being detected. Meanwhile, 0.524 bit of every bit of the secret message can be eavesdropped on without being detected. Secondly, an inner receiver can take the intercept–measure–resend attack strategy to eavesdrop on half of the identity string of the other’s definitely without being checked. In addition, an alternative attack called the CNOT-operation attack is discussed. As for the multi-party QBC protocol, the attack efficiency increases with the increase of the number of users. Finally, the QBC protocol is improved to a secure one.

Quantum key distribution protocol using random bases

In order to enhance the quantum key distribution (QKD) security, a new protocol, “QKDPRB” based on random bases is proposed. It consists of using standard encoding bases moving circularly with a variable rotational angle [Formula: see text] which depends on angular velocity [Formula: see text]; thus, the traditional bases turn into relative ones. To prove the security and the efficiency of the protocol, we present a universal demonstration which proves a high level security of the proposed protocol, even in the presence of the intercept and resend attack. Finally, the QKDPRB may improve the security of QKD.

Secure N-dimensional simultaneous dense coding and applications

Simultaneous dense coding (SDC) guarantees that Bob and Charlie simultaneously receive their respective information from Alice in their respective processes of dense coding. The idea is to use the so-called locking operation to “lock” the entanglement channels, thus requiring a joint unlocking operation by Bob and Charlie in order to simultaneously obtain the information sent by Alice. We present some new results on SDC: (1) We propose three SDC protocols, which use different N-dimensional entanglement (Bell state, W state and GHZ state). (2) Besides the quantum Fourier transform, two new locking operators are introduced (the double controlled-NOT operator and the SWAP operator). (3) In the case that spatially distant Bob and Charlie have to finalize the protocol by implementing the unlocking operation through communication, we improve our protocol’s fairness, with respect to Bob and Charlie, by implementing the unlocking operation in series of steps. (4) We improve the security of SDC against the intercept–resend attack. (5) We show that SDC can be used to implement a fair contract signing protocol. (6) We also show that the N-dimensional quantum Fourier transform can act as the locking operator in simultaneous teleportation of N-level quantum systems.

Quantum private comparison protocol with cloud quantum computing

SummaryBecause privacy problems with big data impede progress at all phases of the pipeline that can create value from data, Alice and Bob have to perform private queries in order to obtain the private comparison results of big data. Suppose that the cloud devices are with the capacity of conventional and quantum computation, an efficient quantum private comparison protocol with ring‐trip transmission by safe cloud quantum computing in the quantum Internet is proposed. Two participant parties Alice and Bob, with the help of a semi‐trusted third party and cloud device by simple quantum measurements and mathematical operation, can compare the equality of their secret information without revealing the content of secret information. We show that our protocol can resist the eavesdropper Eve's intercept–resend attack, entangle–measure attack, and Trojan horse attack to cloud device, participant's intercept–measure–resend attack, and third party's attack. The qubit efficiency of our protocol approaches to 100%. We also analyze the connection between Eve's obtained information and the fidelity of secret information in detail. Copyright © 2015 John Wiley & Sons, Ltd.

Quantum key distribution with several intercepts and resend attacks with partially non-orthogonal basis states

The effect of partially non-orthogonal basis states for several intercept and resend attacks of the Bennett–Brassard cryptographic protocol has been studied. The quantum error and the mutual information are computed for arbitrary angles η of the non-orthogonal basis states. It is found that the secure information depend strongly on the angle η, the probability of intercepts and resend attack and the number of eavesdropper. Besides, it is found that for any eavesdroppers number N≥2, the protocol is more secured for (π/2)<η<(3π/2), while for N=1, the protocol is more secured for η=π/2 or 3π/2 which correspond to the totally orthogonal basis states.

Two-way and one-way quantum cryptography protocols

We present two quantum cryptography protocols. The first one generalizes the concept of the two-way deterministic protocol to work with qudits in prime d-dimensional system where d is odd. The second protocol makes use of the tomographically complete set construction for odd d-dimensional systems where d=p1p2 to modify the BB84 protocol to work with qudits of such systems. The securities of the two protocols are analyzed according to the intercept and resend attack.

Cryptanalysis and improvement of a quantum secret sharing scheme based on χ-type entangled states

In the paper [2010 Chin. Phys. B 19 050306], Yang et al. put forward a novel three-party quantum secret sharing protocol of secure direct communication based on χ-type entangled states, they claimed that the scheme is secure. However, in this paper, we study the security of the protocol and find that it is insecure. Applying intercept and resend attack, the agent Bob can obtain Alice's secret without the help from the other agent Charlie. In the end, we give our effective modification for its improvement.

Intercept–resend attacks on Chen et al.'s quantum private comparison protocol and the improvements

Recently, Chen et al. presented a novel quantum private comparison (QPC) protocol using triplet GHZ state to enable two parties to compare the equality of their information without revealing the content. The protocol is rather promising because it only requires single-photon measurement with the help of a semi-honest third party to complete the secret comparison. However, this study will point out that a weakness could occur in the eavesdropping check phase. That is, an intercept–resend attack could be launched by one of the two participants to reveal the information content of the other participant—a result that contradicts to the security requirement of a QPC. Fortunately, two solutions are possible to avoid the attack.

After-gate attack on a quantum cryptosystem

We present a method to control the detection events in quantum key distribution systems that use gated single-photon detectors. We employ bright pulses as faked states, timed to arrive at the avalanche photodiodes outside the activation time. The attack can remain unnoticed, since the faked states do not increase the error rate per se. This allows for an intercept–resend attack, where an eavesdropper transfers her detection events to the legitimate receiver without causing any errors. As a side effect, afterpulses, originating from accumulated charge carriers in the detectors, increase the error rate. We have experimentally tested detectors of the system id3110 (Clavis2) from ID Quantique. We identify the parameter regime in which the attack is feasible despite the side effect. Furthermore, we outline how simple modifications in the implementation can make the device immune to this attack.

Controlling passively quenched single photon detectors by bright light

Single photon detectors (SPDs) based on passively quenched avalanche photodiodes can be temporarily blinded by relatively bright light, of intensity less than 1 nW. A bright-light regime suitable for attacking a quantum key distribution system containing such detectors is described in this paper. In this regime, all SPDs in the receiver Bob are uniformly blinded by continuous illumination coming from the eavesdropper Eve. When Eve needs a certain detector in Bob to produce a click, she modifies the polarization (or other parameters used to encode quantum states) of the light she sends to Bob such that the target detector stops receiving light, while the other detector(s) continue to be illuminated. The target detector regains single photon sensitivity and, when Eve modifies the polarization again, produces a single click. Thus, Eve has full control of Bob and can perform a successful intercept–resend attack. To check the feasibility of the attack, three different models of passively quenched detectors have been tested. In the experiment, I have simulated the intensity diagrams the detectors would receive in a real QKD system under attack. Control parameters and side effects are considered. It appears that the attack could be practically possible.