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.
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.
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.
Quantum Cryptography is based on the use of subatomic particles (photons) and their intrinsic quantum properties (photon polarization) to develop an unbreakable system. It is not possible to measure the quantum state of any system without affecting the system. This property provides secure transmission of key between sender and receiver. Quantum Cryptography is a way to combine the relative ease and convenience of key exchange in public key cryptography with the ultimate security of a one-time pad. Quantum techniques for key distribution, the classically impossible task of distributing secret information over an insecure channel whose transmissions are subject to inspection by an eavesdropper, between parties who share no secret key initially. Quantum Cryptography uses the principles of Quantum Mechanics to implement a cryptographic system. The key problem which is solved by using quantum techniques is that of eavesdropping detection. The bits are represented as qubits, physically modeled by photons, and communicated over a quantum channel. The polarization states of photons represent 0's and 1's. Keyword: Asymmetric key, Cryptography, Protocols, Quantum, symmetric key
Cryptography is being introduced to secure data. Through Classical Cryptographic technique, we can encrypt our data and secure secret key also. But classical cryptography is based on mathematical techniques where reversing one-way function is possible with sufficient computing power and time. So, Quantum Cryptography is introduced to overcome those drawbacks of traditional classical cryptography. It is based on the values of quantum mechanics and photon. Scientists and researchers have brought up a new key distribution protocol based on Quantum Cryptography is called Quantum Key Distribution (QKD) Protocol. The first QKD protocol BB84 was introduced by Charles Bennett and Gilles Brassard in 1984. After that several QKD protocols have been created. In this paper we have improved BB84 Protocol by removing the drawbacks of the existing algorithm towards Eavesdropping which may not be detected or disclosing large portion of secret key. Steps of the existing BB84 algorithm along with the modified one is described in detail with example and pseudo code. Limitations of BB84 and comparative study of both the existing and the improved one based on their security has been made and described in this current work.
Quantum cryptography is a science that exploits quantum mechanical properties to perform cryptographic tasks.The best-known example of quantum cryptography is quantum key distribution, which offers an information-theoretically secure solution to the key exchange problem.I try to generalize the first quantum key distribution protocol called BB84 and implement the protocol in different steps.The implementation is performed in a fully theoretical manner with a general mathematical base.I propose here an algorithm that can make this protocol more secure.After implementation of the protocol, I tried to find out the result, which I illustrated with figures and tables and also proposed here as a suitable polarizer diagram model that helped me find the outcome of this concept.My proposed polarizer diagram only works to encode and decode the valuable secret key that is transferred from sender to receiver, and the secret key will not be transferred as binary bit data but as a photon particle by the photon polarizer converter.Though the protocol BB84 is the most secure of all quantum key distribution protocols, I tried to make it more secure from any third-party access.
Quantum cryptography provides secret communication, which offers various security factors like confidentiality, integrity, and authentication assurance based on the law of physics. The law of physics states that quantum computing can also be applied into the communication sector, which is particularly in the field of cryptography. Then quantum can significantly distribute the data securely by applying quantum key distribution (QKD), quantum key sharing, etc. In the classical cryptography, it is difficult to compute secret keys using security concepts like key exchange and authentication, etc., and it fails to provide adequate protection during data communication as it needs some effective computation in terms of security. The lack of security in the data communication can be overcome by using the concept of quantum computing. Generally, in quantum computing, elementary quantum systems like polarized photons are used to transmit digital information based on the principle of uncertainty as it gives rise to a significant phenomenon of effective security in terms of communication compared to existing concepts related to cryptography. In quantum computing, the detection ratio for identifying the data which are sent through a communication channel is more difficult as it uses qubits and photons to represent the data that are sent. Quantum channels are used to distribute the information between two users as it passes through the unprotected classical channels as it is unknown to anyone else. Assuming that Alice and Bob use a latent noise channel to send a key, reconciliation is the process of correcting errors between Alice and Bob’s version of the key. This is done by public discussion, which leaks some information about the secret key to an undercover. This chapter gives a discussion on QKD concepts as it helps to provide a secure communication, where the information is broadcasting through a quantum channel. Finally, the various existing quantum protocols are described in relation to some security measures based on QKD, and the standard QKD protocol of BB84 is discussed.
Abstract Cryptography is a scientific method that is used to transmit secret information. In contrast, quantum cryptography depends on physical laws to encrypt information; when the quantum computer appeared, the classic encryption method becomes inefficient. The quantum method is commonly used to distribute keys, a process called as quantum key distribution (QKD). In this paper, we consider the efficiency of the quantum method compared to classical methods. Also, we discuss the security of QKD against several attacks and provide security analysis based on probabilistic models. Additionally, the paper explains how to encrypt random numbers into a sequence of photons using a QKD system for the distribution of a key. This research demonstrates the efficiency and security of QKD in sending and distributing keys between communication parties. Thus, both the sender and the receiver would be able to obtain a security key using the quantum method rather than classical methods.