In this work, a quantum computing based secret key distribution system is proposed. Quantum gates based encryption and decryption circuits are designed and can be used along with conventional encryption schemes such as the Data Encryption Standards (DES), XoR Cipher and Substitution Cipher etc., in the presentation layer. The quantum communication model is implemented and analyzed for both ideal and noisy channel. Using this model if the channel is eaves dropped, the sender and receiver will detect the eavesdropping attempt, the key will be discarded and another key is retransmitted.
In this work, a quantum computing based secret key distribution system is proposed. Quantum gates based encryption and decryption circuits are designed and can be used along with conventional encryption schemes such as the Data Encryption Standards (DES), XoR Cipher and Substitution Cipher etc., in the presentation layer. The quantum communication model is implemented and analyzed for both ideal and noisy channel. Using this model if the channel is eaves dropped, the sender and receiver will detect the eavesdropping attempt, the key will be discarded and another key is retransmitted.
Quantum cryptography is based on quantum mechanics to guarantee secure communication.It allows two parties to produce a shared random bit string known only to them.These random bits can be used as a key to encrypt and decrypt messages.The most important and unique property of quantum cryptography is the ability of the two communicating users to detect the presence of any third party trying to gain knowledge of the key.It is based on fundamental aspects of quantum mechanics.By using quantum entanglement or quantum super positions and transmitting information in quantum states, a communication system can be implemented which detects eavesdropping.Quantum cryptography is used to produce and distribute a key, not to transmit any message data.This key along with certain encryption algorithm, is used to encrypt (and decrypt) a message, which can then be transmitted over a standard communication channel.This paper concentrates on comparison between classical and quantum cryptography as well as survey on various quantum key distribution protocols used to generate and distribute the key among communicating parties.
Secure communication in cryptographic system, relies on secret key which must be exchanged between a sender and a receiver such that it avoids unauthorized access and can be used to encrypt the plain text and decrypt the cipher text. However, advancement in quantum computing raises concern on the security of information exchanged over the web. As the information on the web is made secure using classical cryptographic mechanisms that are only computationally secure and quantum computers with high computational capability can generate the secrete keys in a very short time. In order to make sure that quantum computers do not breach the security of the network, we need to develop some sort of quantum-resistant mechanisms. Quantum key distribution is one of the quantum-resistant-mechanisms which guarantee secure data communication. It leverages quantum mechanics principles by exchanging the key in quantum states called qubits and any attempt to access the key causes disturbance in the qubits yielding change in their behavior or state, hence signaling the presence of an intruder and making it impossible to be accessed. This paper presents a simulation to establish and exchange secrete keys in quantum environment using BB84 protocol and to determine the efficiency of the system, quantum bit error rate is measured and discussed.
Quantum key distribution (QKD) is considered as an ideal method to make secret message unreadable to eaves-dropper but intelligible to the two authorized parties of the communication [1][2][3][4][5][6].In the research of experimental quantum key distribution, single photons and entangled photon pairs are used as the carriers.In quantum key distribution, secret keys are generated first between the communication parties.The security of quantum key distribution is guaranteed by the laws of quantum mechanics.After the quantum key distribution is completed, the communication parties should share secret keys, then the sender encrypts the secret message using the secret keys to form the ciphertext and transmits the ciphertext through a classical channel.The receiver receives the ciphertext and then decrypt the ciphertext to get the secret message.Altogether there are four steps in a secret communication process with QKD: key generation, encryption, transmission and decryption.Here in this review, we review some new development in quantum communication, quantum direct communication (QDC).Quantum direct communication is a form of quantum communication where secret messages can be transmitted through a quantum channel with or without additional classical communications.There are two forms of quantum direct communication, quantum secure direct communication (QSDC) [7{9] and deterministic secure quantum communication (DSQC) [10,11].In QSDC, secret messages are transmitted directly between the communication parties, from sender Alice to receiver Bob, without additional classical communication except those for the necessary eavesdropping check.In other words, the quantum key distribution process and the classical communication of ciphertext are condensed into one single quantum communication procedure in QSDC.Deterministic secure quantum communication is another type of quantum direct communication, such as those proposed in Ref. [10,11], where classical communication is required in order to read out the secret message.As mentioned earlier, to complete a secure communication with the help of QKD, one usually encodes the secret message with an encryption scheme, and the ciphered text is transmitted through a classical channel.With a quantum channel, this procedure can be varied.
Quantum key distribution is an innovative technique to distribute encryption keys without compromise. This paper focuses on the application of this technique to achieve reliable communication in an ever-evolving and increasingly vulnerable environment. Designers of cryptosystems have three basic objectives; designing cryptographic algorithms that adequately scramble the target data, developing strong encryption keys to lock and unlock the algorithm, and securely distributing the keys between communicating devices. The advance of quantum computing technologies threatens to expose the world's most prolific key method overnight. Though quantum computing is not yet a reality, the basic principles have been proven in laboratories. Furthermore, quantum computing has been shown to be especially suited for computations of complex mathematic equations; such as distilling the private keys from the public keys used in public key infrastructures (PKI). In this environment, it's comforting to know that the most advanced technology in the broad field of quantum communications just happens to be a new method of creating and distributing encryption keys. This technology is referred to as quantum key distribution (QKD). QKD technologies shift the current paradigm on two plains. The first is that it uses quantum principles, rather than conventional means, for distributing keys between devices. The quantum principles guarantee the key can not be intercepted during transmission without alerting the users of a compromise. The second shift is derived from the fact that encrypted data can not be intercepted today and decrypted at a later date when the computing power exists to crack the code. This shift is dependant on the use of a combination of QKD and one-time pad. Because of the quantum principles that QKD relies on, when a key is successfully created and shared, it can not be cracked using intercepted data. The keys are derived from a convergence of random operations conducted at the sender and receiver stations. Indeed, neither the sender nor the receiver can determine what the key will be until the entire process is completed. As a piece of our security infrastructure, QKD significantly raises our security posture. This paper explains the application of quantum principals used to enable QKD systems.
Cryptography is processing for securing communication between two people. The opponent wants to know the message that is encrypted using a secret key. Although the opponent can eavesdrop the message sent between the sender and the receiver, the opponent is unable to decrypt to read the message. Therefore, the secret key is very important. The sender and the receiver agree with the secret key in an insecure channel by using key distribution protocol such as the Diffie–Hellman protocol. Since quantum computer is coming soon, Diffie–Hellman protocol is not secure. We will develop a quantum key distribution protocol. The benefit of the quantum system is the quantum state that cannot copy by no‐cloning theorem. Thus, the opponent does not copy and keeps the message that is quantum. In this paper, a novel quantum key distribution protocol between two people (Alice and Bob) based on quantum operators is developed. The opponent (Eve) wants to know the secret key. Although Eve knows this quantum key distribution protocol, Eve does not behave similarly to Alice and Bob. For example, Eve eavesdrops Alice's quantum state that was sent to Bob, and Eve sends another quantum state. Therefore, we cannot control Eve's behavior. So we give the upper bound of mutual information between the user and opponent by using Holevo's bound. We verify the usual security definition for quantum key distribution that is equality‐and‐uniformity and privacy in the mutual information sense.
Quantum Key Distribution (QKD) which is the name of cryptography in quantum environment act as the highest developed area in quantum communication and computing technology (QCIT). \n \nQKD is inventive technology which utilize the laws of quantum to create a cryptographic share key to make the communication system secure. The unique feature of QKD assures eavesdropping detectable during quantum communications which is fascinating for a high-level secure environment.Most of the traditional cryptographic methods which we use currently are based on mathematical scheme or Computational complexity theory which are not completely safe. Using quantum cryptography has been achieved extensive steps in communication security establishment. As the information Unit has been changed from “bit” to Quantum bit (Qubit), a new element has been offered that can guarantee the shared information confidentiality between parties. The confidentiality of system is established via exchanging a secret key through a channel of quantum, the key which we use for encrypting the shared data. This structure has quantum integration which has been developed by physics law and techniques of cryptography. \n \nThis thesis has proposed a modified version of QKD protocol, this new protocol will generate a cryptographic share key for a more efficient, lower cost and secure communication between two parties (sender and Receiver). This new protocol principal is similar to BBM92, but the source of photon moved to sender instead of third-party photon generator, following steps will be executed in this Experiment: \n \n•\tObserve different categories protocols of QKD in details \n•\tThe Quantum Mechanics Visualisation Project (QuVis) is the simulation software that has been used for implementing the proposed protocol [BB84 with spin] among the other three (BBM92, B92 and BB84). \n•\tProbability ratio of error will be tested and compared for all protocols, for this experiment 100 to 5000 photons will be sent. \n \nBy Analysing collected data in this experiment, it will be determined which one of this four protocols lead the detecting of eavesdropping. Simulation software accomplishes the value of error key probability which receiver can use and should not pass over the range limit of 0.25 & 0.5.