Content uploaded by Khaled Elleithy

Author content

All content in this area was uploaded by Khaled Elleithy on Feb 04, 2018

Content may be subject to copyright.

A Novel Secure Quantum Key Distribution

Algorithm

Abstract—Key distribution is the function that delivers a

key to two parties who wish to communicate with each

other in secure manner. Therefore, key distribution must

be secure enough to thwart any attempts to compromise

the system. In this paper we introduce a secure key

distribution system based on quantum theory. The

proposed algorithm provides a secure way to distribute,

or exchange the key that recognizes any comprise of the

quantum communication channel.

Index Terms—Quantum Key Distribution, Quantum

Cryptography

I. INTRODUCTION

In cryptography, key distribution is the function that

delivers a key to two parties who wish to communicate with

each other. The strength of any cryptographic system relies

on Key distribution. Therefore, it is really important to have

a secure key distribution system because if an attacker ever

succeeds in gaining access to the secure or private key, then

s/he can compromise the whole system [1]. Two basic

approaches used in Key distribution system:

1) Symmetric encryption

2) Asymmetric encryption

Key distribution by symmetric encryption means that the

two parties who want to exchange encrypted data must share

the same key. In contrast, Key distribution by asymmetric

encryption means each of the parties must have a pair of

keys called private/public keys., The private key is kept in

secure with each party whereas the public key is used in

exchange of encrypted data [2][3].

On the other hand, quantum key distribution provides the

most secure way to distribute, or exchange secret keys due

to the nature of quantum mechanics and quantum physics. If

the communication channel has been compromised, the

quantum state on the transmitted data will collapse to a

single state, and therefore, get disturbed [4], [5].

II. PROBLEM IDENTIFICATION

The two basic approaches used in Key distribution

system have drawbacks. In Symmetric encryption the major

problem is how to deliver the secure key between the two

parties. In asymmetric encryption the major problem (even

in theory) is calculating the private key from the public key

by the combination of superpower computers, parallel

computation, and time.

In this paper we introduce a new key distribution system

based on quantum theory. The proposed algorithm provides

a secure way to distribute, or exchange the key that

recognizes any comprise of the quantum communication

channel. In section II we provide an overview of related

work. In section III we present the proposed protocol. In

section IV, the protocol is analyzed. Finally, section IV

provides conclusions.

II. RELATED WORK

In Quantum Key Distribution QKD system two parties

that wish to communicate are allowed to create a secret key

based on a random function. In such a system, it is assumed

that the communication channel is vulnerable to an

unauthorized party [6]. Many protocols have been

introduced in literature to solve the quantum communication

problem, such as, BB84 and B92. Although these protocols

were novel when they were introduced, they received over

time a lot of criticism. For instance, BB84 was designed on

the assumption of using weak signal source, near perfect

transmission line, sensitive and fast quantum detectors,

amplifiers, repeaters that are needed to compensate the loss

in the signal. These assumptions might not be practical in

many situations.

Another major problem with quantum communication

channels is the use of highly attenuated lasers as source of

quantum signals. These sources can produce signals that

contain more than one photon. Consequently, a new attack

that exists in quantum world called Photon Splitting Attack.

Abdulrahman Aldhaheri, Khaled Elleithy, Majid Alshammari, Hussam Ghunaim

Computer Science and Engineering Department

University of Bridgeport

aaldhahe@my.bridgeport.edu, elleithy@bridgeport.edu, maalsham@my.bridgeport.edu,

hghunaim@my.bridgeport.edu

For instance, the eavesdropper can measure the number of

existing photons in a quantum signal. Then, it is possible to

split multi-photon signal to keep on copy for the

eavesdropper and sending another copy to the receiver [7].

Moreover, Saikat Guha et al. [8] have discussed that the

Lossy Bosonic channel is one that is possible for a passive

eavesdropper to collect all the photons that do not reach the

receiver, and hence, be able to store these photons in a

quantum memory. They added, for a key to be secured, it

must have very small information about the key.

Sharma et al. [3], have added an improvement of the

existing quantum key distribution model in terms of:

1) no authentication of participant,

2) lack of pre transmission process, and

3) no estimation of attackers’ information.

The authors in [3] include nine steps to overcome on

existed vulnerable models: authentication of participant in

QKD, initialization, quantum transmission, shifting, errors

correction, estimating attackers’ information, dDecision on

continuation, privacy amplification, and getting error free

key. However, in the improvement, an assumption is taken

for all the errors are made by the attacker, which can

enhance the protocol security.

In [9], Sharma et. al. proposed a scheme for using

quantum key distribution in 802.11 networks (mobile

networks) by a modified version of the key distribution. The

Quantum Key Distribution presentedby the authors use

BB84 protocol for the distribution of the cryptographic keys

used by 802.11i.

The authors of [10] developed an algorithm called

Quantum Key Distribution by Using Public Key Algorithm

(RSA). The authors proposed an algorithm that applies some

classical concepts and quantum techniques.As an example

the authors applied public key concepts to enhance user

authentication and data integrity process.

Houshmand et. al. [11] introduced a novel QKD protocol

called An Entanglement-based Quantum Key Distribution

that utilizes entanglement to mitigate eavesdropper. In this

protocol the stream of qubits is divided into a sequence of

qubit pairs and entangling the qubits in each qubit pair by

randomly applying one of the two predefined unitary

transformations before transmission.

Most of the reported work in literature suggests that

quantum key distribution protocols rely on classical channel

at some point [12], [13], [10]. The proposed protocol in [14]

eliminates the need of classical channel, which is used for

the confirmation and the validation of exchanged data

between the sender and the receiver. It allows the sender and

the receiver to agree on a session key by sending the data

many times over the quantum channel. However, this

protocol introduces significant overhead as the sender and

the receiver have to repeat the process for 20 rounds. Within

each round, the data will be sent twice, once by the sender

and another time by the receiver.

On the other hand, the data transmission rate of today’s

quantum channel is very low. A single photon will allow as

low as 100 bits/s [14]. The national Institute of Standards

and Technology (NIST) has achieved 1000 bits/s over a 730

meter of free space link. The impact of the distance on the

secret key generation rate is negative. The longer the

distance the lower the secret key generation rate. In [15], the

authors provide a summary of the key generation rate

compared to the distance for a quantum key distribution

point-point communication.

The proposed protocol in [12] has a logarithmic

relationship between the size of the key and the number or

rebounds needed. However, it still uses a classical channel.

The use of classical channel could improve the efficiency of

quantum key distribution if utilized correctly [10].

III. PROPOSED PROTOCOL

The proposed protocol main objective is to supersede the

deficiencies found in BB84 and B92 protocols by

eliminating the need for the two communicating parties to

confirm their used basis over a public channel. The new

concept relies on benefiting from the currently available

public key cryptography.

In this implementation, Alice (sender) wants to

communicate with Bob (receiver) over a quantum channel.

Therefore, it is essential to agree on a specific basis to be

able to do so. In the proposed protocol, a classical public

key cryptography is used to send the basis which allows the

two communicating parties to communicate over a quantum

channel. The steps of the protocol are shown in Figure 1 and

are as follows:

Steps:

1) Alice (sender) generates a random basis and a

random nonce.

2) Alice encrypts the basis concatenated with the

nonce using her private key, PRAlice , to provide

authentication service, and Bobs (receiver) public

key PUBob to provide the confidentiality.

3) Alice sends the encrypted basis via a classical

channel to Bob.

4) When Bob receives the encrypted message, he will

be the only one who is able to decrypt it using his

own private key PRBob. He would, as well, be

confident that the message was actually sent from

Alice by decrypting it using Alices Public key

PUAlice.

5) Bob generates a random session key Ks, and sends

it concatenated with the nonce to Alice using the

quantum channel.

6) Alice can verify that the message is from Bob by

verifying the nonce.

7) Alice and Bob can communicate on the same

classical channel using the session Ks generated by

Bob.

IV. ANALYSIS OF THE PROPOSED PROTOCOL

The proposed protocol takes advantage of the current

public key cryptography protocols and the physical features

of the quantum channels. It provides authentication and

confidentiality.

The main purpose of the proposed protocol is to ensure

that a session key is delivered to the communicating parties

in a secure manner. It eliminates the inefficiency introduced

by preceding quantum key distribution protocols, which

requires that the sender and the receiver communicate over

the quantum channel for many rounds just to agree on a

basis for the quantum communication, up to 20 rounds in the

protocol proposed by Zamani [14].

We’ve been able to eliminate this by having the user

who’s requesting the communication session to generate a

random basis, a random nonce, and to send it to the receiver

over a classical channel.

The sender, then, concatenates the randomly generated

basis along with the randomly generated nonce and sent

them to the receiver encrypted using public key

cryptography. The sender uses her own private key in the

encrypted message to provide authentication, and uses the

receiver public key to provide confidentiality.

The receiver, Bob, should be able to verify that the

message is indeed from Alice because he can decrypt it

using Alice’s private key PRAlice. He should be confident that

the message is secured because it’s encrypted using his

public key PUBob and could only be decrypted using his

private key PRBob, which no one knows but him.

When Alice receives the session key generated,

KSession,by Bob she receives it over the quantum channel

encoded using the random basis she has generated earlier at

the beginning of the session. She received the original

Nonce that she has also created along with the random basis.

She should be confident that the session key KSession has been

generated by Bob because it has the Nonce she sent to Bob

earlier.

V. CONCLUSION

In this paper we propose a new protocol that mitigates

the deficiencies found in BB84 and B92 protocols by

eliminating the need for the two communicating parties to

confirm their used basis over a public channel.

The proposed quantum key distribution protocol takes

advantages of the strengths of quantum channels.

Furthermore, it builds on the strengths of the public key

cryptography. This protocol eliminates the unwanted

redundancy introduced in previous protocols, and thus,

encourages us to implement it without worrying about the

low data transmission rate that most quantum channels

suffer from.

REFERENCES

[1] S. William and W. Stallings, Cryptography and

Network Security, 6th ed. Pearson Education, 2011.

[2] M. Bala Krishna and M. Doja, “Symmetric key

management and distribution techniques in wireless ad

hoc networks,” in Computational Intelligence and

Communication Networks (CICN), 2011 International

Conference on. IEEE, 2011, pp. 727–731.

[3] R. D. Sharma and A. De, “A new secure model for

quantum key distribution protocol,” in Industrial and

Information Systems (ICIIS), 2011 6th IEEE

International Conference on. IEEE, 2011, pp. 462–466.

[4] N. S. Yanofsky and M. A. Mannucci, Quantum

computing for computer scientists. Cambridge

University Press Cambridge, 2008, vol. 20.

[5] M. D. H. Kulkarni, “Research directions in quantum

cryptography and quantum key distribution,”

International Journal of Scientific and Research

Publications, vol. 2, no. 6, June 2012.

[6] H. P. Yuen, “Kcq: A new approach to quantum

cryptography i. general principles and qubit key

generation,” Tech. Rep., 2003.

[7] H.-K. Lo, X. Ma, and K. Chen, “Decoy state quantum

key distribution,” Physical Review Letters, vol. 94, no.

23, p. 230504, 2005.

[8] S. Guha, M. Takeoka, H. Krovi, M. M. Wilde, and C.

Lupo, “Secret key generation over a lossy optical

channel with a passive quantum eavesdropper: Capacity

bounds and new explicit protocols,” submitted to AQIS,

vol. 2013, 2013.

[9] A. Sharma, V. Ojha, and S. Lenka, “Quantum key

distribution in wlan 802.11 networks,” in Networking

and Information Technology (ICNIT), 2010

International Conference on. IEEE, 2010, pp. 402–405.

[10] A. Odeh, K. Elleithy, M. Alshowkan, and E.

Abdelfattah, “Quantum key distribution by using public

key algorithm (rsa).” London, United Kingdom: Third

International Conference on Innovative Computing

Technology (INTECH), August 2013.

[11] M. Houshmand and S. Hosseini-Khayat, “An

entanglement-based quantum key distribution protocol,”

in Information Security and Cryptology (ISCISC), 2011

8th International ISC Conference on. IEEE, 2011, pp.

45–48.

[12] M. Alshowkan, K. Elleithy, A. Odeh, and E.

Abdelfattah, “A new algorithm for three-party quantum

key distribution,” in 2013 Third International

Conference on Innovative Computing Technology

(INTECH), London, United Kingdom, August 2013.

[13] C. H. Bennett, G. Brassard et al., “Quantum

cryptography: Public key distribution and coin tossing,”

in Proceedings of IEEE International Conference on

Computers, Systems and Signal Processing, vol. 175,

no. 0. New York, 1984.

[14] F. Zamani and P. K. Verma, “A qkd protocol with a

two-way quantum channel,” in Advanced Networks and

Telecommunication Systems (ANTS), 2011 IEEE 5th

International Conference on. IEEE, 2011, pp. 1–6.

[15] L. Oesterling, D. Hayford, and G. Friend,

“Comparison of commercial and next generation

quantum key distribution: Technologies for secure

communication of information,” in Homeland Security

(HST), 2012 IEEE Conference on Technologies for,

2012, pp. 156–161.