A Novel Secure Quantum Key Distribution
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
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 . 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 .
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 , .
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
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 . 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
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
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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 .
Moreover, Saikat Guha et al.  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. , 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  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 , 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  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.  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 , , . The proposed protocol in 
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 . 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 , the
authors provide a summary of the key generation rate
compared to the distance for a quantum key distribution
The proposed protocol in  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 .
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:
1) Alice (sender) generates a random basis and a
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
5) Bob generates a random session key Ks, and sends
it concatenated with the nonce to Alice using the
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
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
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 .
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
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
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