Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

International Conference on Information and Communication Technologies: From Theory to Applications (ICTTA)

QKD: Recovering Unused Quantum Bits

Abdulla M. Abu-ayyash, Naim Ajlouni

Published Apr 1, 2008• 5 citations
Publisher

Abstract

Practical quantum key distribution gain is usually less than the theoretical limit, this is due to the imperfection of physical devices, quantum channels, and the lost qubits due to test carried out for for the identification of the presence of an eavesdropper and the consequence reduction of obtained knowledge. In this paper a technique is presented to recover some of the unused qubits which result in an increase in the gain of the QKD protocols, in this research it was found that for the BB84 the recovered qubits can be as much as 11% of the initial key bits. This technique is based on discovering the relationship between the initial key bits and the original random bits which will aid in the recovery process of the unused qubits ( unused qubits are the bits which are assumed to be lost at the start of the process due to the random process and for BB84 it is assumed to be around 50% of the generated key bits).

DOI
10.1109/ictta.2008.4530283

Related papers

Permutated recovering unused quantum bits

Abdulla M. Abu-ayyash, Naim Ajlouni

Some quantum key distribution (QKD) technics - BB84, B92 [4], [5] for example - have a gain problem comparing the fnal key to the generated pulses of quantum particles. RUQB [1] technique improves the gain of BB84 by 5.5%, the improvement was achieved by fnding the relationship among the random bits that where initially generated, then exchanging this relationship to aid in recovery of some lost bits. This research permutate the sets that RUQB uses (hence P-RUQB) to have better gain, it was found that about 30% gain can be recovered by using about 8 permutations in ideal situation.

IEEE Jordan Conference on Applied Electrical Engineering and Computing Technologies•Dec 1, 2011•0 citations

Entanglement-Enhanced Quantum Key Distribution

Olli Ahonen

Quantum key distribution (QKD) allows two spatially separated parties to securely generate a cryptographic key. The first QKD protocol, published by C. H. Bennett and G. Brassard in 1984 (BB84), describes how this is achieved by transmitting individual qubits and exchanging classical authenticated information. Any attempt to eavesdrop on the protocol introduces errors detectable by the legitimate parties. This Licentiate Thesis studies the recently introduced EEQKD protocol which builds on BB84. In EEQKD, the qubits sent individually in BB84 are entangled and thus not directly available to an eavesdropper who is, in this protocol, provided only one-by-one access to the transmission. The maximal information an eavesdropper can gain using a straightforward intercept-resend (IR) attack, is obtained for a given error rate. The secure key generation rate of EEQKD is estimated in practical scenarios including qubit loss and quantum channel noise. In addition, an exquisite vulnerability is exposed: For a particular setting of qubit entanglement, paradoxically proving most useful in the face of an IR attack, EEQKD reduces to BB84. Part of this research has been published in O. Ahonen et al., Physical Review A 78, 032314 (2008).

arXiv:0903.2117•Mar 12, 2009•0 citations

Using Permutations to Enhance the Gain of RUQB Technique

Abdulla M. Abu-ayyash, Naim Ajlouni

Quantum key distribution (QKD) techniques usually suffer from a gain problem when comparing the final key to the generated pulses of quantum states. This research permutes the sets that RUQB (Abu-ayyash & Ajlouni, 2008) uses in order to increase the gain. The effect of both randomness and permutations are studied; While RUQB technique improves the gain of BB84 QKD by 5.5% it was also shown that the higher the randomness of the initial key the higher the gain that can be achieved, this work concluded that the use of around 7 permutations results in 30% gain recovery in an ideal situations.

International Journal of Information Technology and Web Engineering•Apr 1, 2012•1 citation

Increasing the Protocol Gain of Quantum Cryptography

Firas A. Al-Juboori, Noor Kareem Juma, a Al-Mandilawi

Quantum cryptography is a technique to distribute a sequence of truly random and unconditionally secure bits over a secure communication by applying the phenomena of quantum physics. The distributed secret bits perform the secret key which is used later to encrypt messages with an encryption algorithm, usually the One-Time-Pad is used. Quantum Key Distribution solves the security problem in classical cryptography by depending on the laws of physics which is focusing on the physics of information. Quantum protocol gain usually is low due to the quantum channel noise and the difference between the photon polarization at the sender and receiver side; in this research, a method is proposed to increase the protocol gain without decreasing the security level of quantum key. BB84 quantum key distribution algorithm is implemented and simulated with MATLAB R2010a simulation; and a comparison is made with A. Singh and N. Sharma [14] results.

Engineering and Technology Journal•Sep 1, 2013•0 citations

Statistical analysis for random bits generation on quantum key distribution

Omer K. Jasim Mohammad, Safia Abbas, El-Sayed M. El-Horbaty +1 more

Recently, Quantum cryptography researchers utilize the quantum keys, in order to provide a more trusted environment for both key distribution and management processes. The quantum keys are generated based on quantum mechanics phenomena. However, all events for the quantum key generation rely on exchanging photons between parties over limited distances. So, in this paper, random tests algorithms, such as NIST and DIEHARD, are implemented to test and evaluate the randomness rates for quantum keys generation. After then, the initialized vector, which is the seed of the symmetric encryption algorithms, is established based on specific analysis to be a key for the algorithms. The paper utilizes the (BB84) quantum key distribution (QKD) protocol based on two different innovated modes, the raw and privacy modes.

International Conference on Cyber Security, Cyber Warfare and Digital Forensic (CyberSec)•Apr 1, 2014•7 citations

Causes of bit error and error correction for quantum key distribution protocols

Rushui Fang, Vladimir V. Nikulin

Quantum key distribution protocols (QKD) identify eavesdroppers on quantum channel based on laws of quantum mechanics. In the original BB84 protocol, unauthorized measurements on qubits are discovered after Alice and Bob sacrifice some random resulting key bits as a test and find out a mismatch rate. Decoy state protocol alerts photon number splitting attack when the decoy multiphoton pulses deliberately positioned by Alice are registered abnormally higher at Bob’s detectors than the single photon pulses are. E91 protocol is the first QKD protocol that ever brought about entangled atoms. Based on Bell’s theorem, a probability coefficient is constrained within a fixed range under the circumstances of interception. While in practice, bit error rate (BER) is not necessarily associated with vicious eavesdropping. Detection inefficiency, transmission loss, imperfect entanglement sources and many other factors contribute as false alarms. Error correction is an essential post-processing procedure to tolerate implementation limits, yet secure the accuracy of the transmitted key. Quantifying third party contaminations also helps setting an optimal BER threshold to decide if one should abandon all previous communications. In this work, we summarize major causes of bit error in various practical QKD protocols mentioned above and study whether error correction models, such as low-density parity-check code (LDPC), perform accordingly to different kinds of errors.

Quantum Nanophotonic Materials, Devices, and Systems•Sep 3, 2019•0 citations
Practical quantum key distribution gain is usually less than the theoretical limit, this is due to the imperfection of physical devices, quantum channels, and the lost qubits due to test carried out for for the identification of the presence of an eavesdropper and the consequence reduction of obtained knowledge. In this paper a technique is presented to recover some of the unused qubits which result in an increase in the gain of the QKD protocols, in this research it was found that for the BB84 the recovered qubits can be as much as 11% of the initial key bits. This technique is based on discovering the relationship between the initial key bits and the original random bits which will aid in the recovery process of the unused qubits ( unused qubits are the bits which are assumed to be lost at the start of the process due to the random process and for BB84 it is assumed to be around 50% of the generated key bits).
Some quantum key distribution (QKD) technics - BB84, B92 [4], [5] for example - have a gain problem comparing the fnal key to the generated pulses of quantum particles. RUQB [1] technique improves the gain of BB84 by 5.5%, the improvement was achieved by fnding the relationship among the random bits that where initially generated, then exchanging this relationship to aid in recovery of some lost bits. This research permutate the sets that RUQB uses (hence P-RUQB) to have better gain, it was found that about 30% gain can be recovered by using about 8 permutations in ideal situation.
Quantum key distribution (QKD) allows two spatially separated parties to securely generate a cryptographic key. The first QKD protocol, published by C. H. Bennett and G. Brassard in 1984 (BB84), describes how this is achieved by transmitting individual qubits and exchanging classical authenticated information. Any attempt to eavesdrop on the protocol introduces errors detectable by the legitimate parties. This Licentiate Thesis studies the recently introduced EEQKD protocol which builds on BB84. In EEQKD, the qubits sent individually in BB84 are entangled and thus not directly available to an eavesdropper who is, in this protocol, provided only one-by-one access to the transmission. The maximal information an eavesdropper can gain using a straightforward intercept-resend (IR) attack, is obtained for a given error rate. The secure key generation rate of EEQKD is estimated in practical scenarios including qubit loss and quantum channel noise. In addition, an exquisite vulnerability is exposed: For a particular setting of qubit entanglement, paradoxically proving most useful in the face of an IR attack, EEQKD reduces to BB84. Part of this research has been published in O. Ahonen et al., Physical Review A 78, 032314 (2008).
Quantum key distribution (QKD) techniques usually suffer from a gain problem when comparing the final key to the generated pulses of quantum states. This research permutes the sets that RUQB (Abu-ayyash & Ajlouni, 2008) uses in order to increase the gain. The effect of both randomness and permutations are studied; While RUQB technique improves the gain of BB84 QKD by 5.5% it was also shown that the higher the randomness of the initial key the higher the gain that can be achieved, this work concluded that the use of around 7 permutations results in 30% gain recovery in an ideal situations.
Quantum cryptography is a technique to distribute a sequence of truly random and unconditionally secure bits over a secure communication by applying the phenomena of quantum physics. The distributed secret bits perform the secret key which is used later to encrypt messages with an encryption algorithm, usually the One-Time-Pad is used. Quantum Key Distribution solves the security problem in classical cryptography by depending on the laws of physics which is focusing on the physics of information. Quantum protocol gain usually is low due to the quantum channel noise and the difference between the photon polarization at the sender and receiver side; in this research, a method is proposed to increase the protocol gain without decreasing the security level of quantum key. BB84 quantum key distribution algorithm is implemented and simulated with MATLAB R2010a simulation; and a comparison is made with A. Singh and N. Sharma [14] results.
Recently, Quantum cryptography researchers utilize the quantum keys, in order to provide a more trusted environment for both key distribution and management processes. The quantum keys are generated based on quantum mechanics phenomena. However, all events for the quantum key generation rely on exchanging photons between parties over limited distances. So, in this paper, random tests algorithms, such as NIST and DIEHARD, are implemented to test and evaluate the randomness rates for quantum keys generation. After then, the initialized vector, which is the seed of the symmetric encryption algorithms, is established based on specific analysis to be a key for the algorithms. The paper utilizes the (BB84) quantum key distribution (QKD) protocol based on two different innovated modes, the raw and privacy modes.
Quantum key distribution protocols (QKD) identify eavesdroppers on quantum channel based on laws of quantum mechanics. In the original BB84 protocol, unauthorized measurements on qubits are discovered after Alice and Bob sacrifice some random resulting key bits as a test and find out a mismatch rate. Decoy state protocol alerts photon number splitting attack when the decoy multiphoton pulses deliberately positioned by Alice are registered abnormally higher at Bob’s detectors than the single photon pulses are. E91 protocol is the first QKD protocol that ever brought about entangled atoms. Based on Bell’s theorem, a probability coefficient is constrained within a fixed range under the circumstances of interception. While in practice, bit error rate (BER) is not necessarily associated with vicious eavesdropping. Detection inefficiency, transmission loss, imperfect entanglement sources and many other factors contribute as false alarms. Error correction is an essential post-processing procedure to tolerate implementation limits, yet secure the accuracy of the transmitted key. Quantifying third party contaminations also helps setting an optimal BER threshold to decide if one should abandon all previous communications. In this work, we summarize major causes of bit error in various practical QKD protocols mentioned above and study whether error correction models, such as low-density parity-check code (LDPC), perform accordingly to different kinds of errors.