The reported research in literature for message transformation by a third party does not provide the necessary efficiency and security against different attacks. The data transmitted through the computer network must be confidential and authenticated in advance. In this paper, we develop and improve security of the braided single stage quantum cryptography. This improvement is based on a novel authentication algorithm by using signature verification without using the three stages protocol to share the secret key between the sender and receiver. This approach will work against attacks such as replay and man-in-the-middle by increasing the security as well as the over efficiency, reducing the overhead through using three stages and increasing the speed of the communication between two parties.
The reported research in literature for message transformation by a third party does not provide the necessary efficiency and security against different attacks. The data transmitted through the computer network must be confidential and authenticated in advance. In this paper, we develop and improve security of the braided single stage quantum cryptography. This improvement is based on a novel authentication algorithm by using signature verification without using the three stages protocol to share the secret key between the sender and receiver. This approach will work against attacks such as replay and man-in-the-middle by increasing the security as well as the over efficiency, reducing the overhead through using three stages and increasing the speed of the communication between two parties.
The security of Quantum Secure Direct Communication (QSDC) and its authentication procedure based on multiple stages is analyzed. The security analysis shows that the process of authentication is required to be done three times based on the usage of unitary transformation that is only known between Alice and Bob. In the proposed protocol, a secure quantum handshake is utilized to share the secret polarization angle and an authentication key at the initial stage of authentication over the quantum channel. The symmetry key is used in this work to protect user data communication within the QSDC protocol, where the same secret key is used to encrypt and decrypt the message. This work adopts the information travel time (ITT) by allowing the sender to detect any interference from third parties. In addition, the operation of the Pauli-X quantum gate increases Eve’s difficulty in stealing the information. The information transmitted is then continued by sending photons once in the quantum channel, which improves the efficiency without losing the message’s security. In addition, to securely transfer the stream of messages, the proposed protocol is operated in single-stage, and the authentication is applied bit-by-bit, thus reducing the transmission time. Security checks are carried out along the data transmission process. Compared to previous protocols, this new initial authentication protocol has remarkable advantages since it does not require public communication to pre-share the authentication key and secret angles before the onset of the transmission, therefore, reducing the communication cost. Moreover, the secret authentication key and polarization angles are updated after a number of bits are sent to increase the security level. The verification process is also conducted to ensure the symmetry of the sender and receiver. The analyses presented herein demonstrate that the proposed authentication protocol is simple and secure in order to ensure the legitimacy of the users.
A quantum high secure direct communication with authentication protocol is proposed by using single photons. The high security of the protocol is achieved on levels. The first level involves the verification of the quantum channel security by using fake photons. The authentication process is also ensured by the fake photons. The second level of security is given by the use of multiple polarization bases. The secret message is encoded in groups of photons; each single character of the message is associated with m (m≥7) photons. Thus, at least 27(128) characters will be encoded. In order to defeat the quantum teleportation attack, the string of bits associated to the secret message is encrypted with a secret string of bits by using XOR operator. Encryption of the sender's identity string and the receiver's identity string by the XOR operator with a random string of fake photons defends quantum man-in-the-middle attack efficiently. Quantum memory is required to implement our protocol. Storage of quantum information is a key element in quantum information processing and provides a more flexible, effective and efficient communication. Our protocol is feasible with current technologies.
In order to mitigate the problem of low transmission rate and limited communication distance in Quantum Communication (QCs), multiphoton over multi-stages approach has been proven to be a possible alternative to the conventional single photon approach. Multiphoton has the ability to improve the range of distances and key generation rate over multi-stages photon transmission. However, the determination of optimal mean photon numbers and number of stages in multiphoton approach remains a key challenge to make the protocols well utilized during their operations. Following this concern, three problems and their corresponding proposed solutions in this thesis are presented below: Firstly, the existing multiphoton approaches involve multiple photons to travel throughout a number of stage. Furthermore, extra time is required to update the polarization angle of optical device for encoding purposes. These conditions would result in an increase in the total transmission time of the photons to be transmitted over the quantum channel. Accordingly, a Hybrid M-Ary in Braided Single-Stage (HMBSS) approach by utilizing data compression concept is proposed to address these issues. In HMBSS, the sender is able to compress the secret message using Huffman encoding over the braided single-stage operation. This compression mechanism has reduced the number of bits required to represent a string of symbols, thereby reducing the time to encode the photons. The simulation experiments shows that HMBSS achieved promising result by 75.9% and 91.7% total average transmission time decrease as compared to the well-known Multiphoton-BSS, Multiphoton-M-ary and Multiphoton-TSIV. Secondly, providing strong authentication is the main focus in this research which aims to make multiphoton QC secure against variety types of attacks. Current authentication procedure in multiphoton QC requires public agreement to pre-share the authentication key and secret angles before onset of the transmission, therefore increasing the communication cost. As a solution, a Secure Secret Authentication Key (SSAK) is proposed. In SSAK, the quantum handshake scheme is used to share initial secret polarization angle and authentication key which is utilized before quantum communication session. The results of simulation experiments reveal that SSAK significantly outperformed the Three-stage protocol in terms of average covered angle by Eve. The simulation experiments and security analysis of initial authentication and transmission of messages verified that an eavesdropper is unable to disclose any information about the transmitted message or the authentication key. Lastly, most of the proposed QKD protocol employs a single-beam set up to transmit the photons over the free space optic which results in low bit rate and limited distance coverage due to high impact of geometrical loss. To deal with this, a transmission technique of Multiphoton Quantum Communication using multiple beam concept (MQC-MB) is proposed. Comparison is conducted in terms of total loss and received power on different number of beam shows that 4-beam is acceptable to be adapted in MQC-MB. The statistical analysis shows that such approach has reduced the total attenuation by 6dB compared to single-beam setup.
A new three-party quantum secure direct communication protocol with authentication is proposed. The advantage of the scheme is that through authentication one can confirm the sender's legitimate identity, partially entangled states used as information carrier are easy to prepare and store, there is no need to transmit quantum states with secret message in quantum channel and two users can simultaneously communicate with the third party. In ideal channel, the protocol is secure against incoherent attack.
Quantum secure direct communication (QSDC) is a branch of quantum cryptography which exploits laws of physics and was recently proposed for securing information transferred from sender to receiver without relying on computational complexity. Instead of an entangled photon, the quantum cryptography employs two other approaches, single photon and multiphoton for encoding the messages. The multiphoton was proposed to outperform the weaknesses of a single photon by introducing the multiplicity of a photon to perform data encryption tasks. Despite the advantages of multiphoton, the transmission time to transfer the encoded data is still regarded as a critical issue. Most of the multiphoton approaches require multiple photons to travel along a number of stages. Moreover, extra time is needed to change the polarization angle of the optical device for encoding purposes. These situations have resulted in an increase in source redundancy, which subsequently leads to an increase in the transmission time. In this paper, a compression message approach is proposed to mitigate the substantial increase in time used for the data transmission processes. The proposed compression approach, namely, hybrid M-ary in a braided single stage (HMBSS) is based on the lossless data encoding such that the number of photons is reduced in the data transmission stage. Extensive simulation experiments have been conducted to test the performance of the proposed approach against some selected multiphoton approaches. The results show that the proposed approach outperforms braided single-stage, M-ary three-stage and initialization vector in terms of reducing total average transmission time to encode the photon by about 75.9% and 91.7%, respectively. Furthermore, the HMBSS reduces the overhead on the transmission channel by minimizing the number of message's bits by about 45% in average even when the length of the message increases during the transmission as compared to others.
Inspired by quantum secure direct communication, a three-party quantum secret sharing approach is proposed. In the preparation phase, the sender shares a GHZ state among users. After she ensures about the security of the channel, she generates an auxiliary GHZ state and keeps it. Then she encodes three-bit information on the GHZ states, by applying the appropriate gates on her qubits. In the decoding phase, the three parties measure their qubits. The receivers achieve no information on the encoded message individually and just when they know the others' measurement results have access to the secret message. The security of the preparation phase against various attacks is investigated. Since no qubits carrying the message are transmitted, the protocol is completely secure, if the perfect quantum channel is used. The proposed approach has a better efficiency as compared to the previous ones.