Quantum Cryptography

Using this principle, QC provides unconditional security to protect our data. A unit of quantum information is also called as qubit or quantum bit. A qubit can have values 0 or 1 which can retain superposition state of these two bits. Using Quantum cryptography, secret key is obtained, and then it can be used with classical cryptographic techniques as the one- time-pad to allow the parties to interact. In Quantum Key Distribution, we consider two peoples as Alice and bob which obtains some quantum states and measures them. A QKD system contains two channels such as a quantum channel which is only used to transmit single photon transparent optical path and a classical channel which is channel can be a conventional IP channel. The key can be generated by communicating through quantum channels and then they communicate through classical channels to determine their measurements results leads to secret key bit. QKD systems continually generate new private keys that share automatically on both sides.

Quantum cryptography, the study of cryptographic protocols that are based on quantum mechanical principles (see Section 12.6 of [9] for an introduction) is an ideal candidate for graphical analysis. Indeed, proofs in quantum cryptography are often long and complicated even when the central idea of the proof is relatively clear. Pictures are regularly used as a conceptual aid in discussions of quantum cryptography, but it would be beneficial for both accessibility and rigor if proofs themselves could be expressed as pictures. For this reason, we believe that the field of quantum cryptography can benefit from the abstract methods of categorical quantum mechanics [8].

Depending on the theory of physics, quantum cryptography does not make it possible to eavesdrop on transmitted information. Quantum cryptographic transmission encrypts the 0s and 1s of digital signal on individual particles of light known as photons. The modern optical transmission states that the digital signal (0’s and 1’s)represents strength and weakness of light as they are made up of tens of thousands of photons in which each express the same information. Even if the signal is eavesdropped (i.e., several photons are stolen) during transmission, it is not detected. On the other hand, if any third party detects the signal, then the information on the photons is suddenly transformed, meaning that it is immediately noticeable that Eve has appeared and the third party is not able to decrypt the information.

Since digital signatures also based on public key cryptography and once it is easy to break them, then digital signatures will also not be secure any more. For that purpose also quantum cryptography has received a lot of attention. Here we will present one simple approach to generate quantum digital signature using quantum public cryptography based on quantum trapdoor one-way function

Above characteristics can be considered negative but these drawbacks are turned into positive applications for quantum cryptography. Heisenberg Uncertainty principle says that we cannot measure quantum state of system without disturbing it. So when light particle is polarized, we can know the polarization only at the time of measuring it.

Quantum cryptography applications seem promising despite having implementation challenges. Still there is a lot to be done to develop quantum cryptography infrastructure. Many government agencies and corporate have started planning for quantum proof security arrangements. It is impossible to predict the future but scientists are expecting practical quantum computer by 2045 to be a reality. This does not mean that quantum computers are going to replace classical computers; still there is a need to define protocols and architecture to interface both worlds together.

These two classes of eavesdropping strategies are among the most frequently discussed attacks in the literature on quantum cryptography. The intercept- resend attack is the most ‘classical’ attack and one of the very few attacks which can be realised with present-day technology, while the superior channel attack has been shown to be the ideal eavesdropping strategy for some quantum cryptography schemes. I have proven that the scheme discussed here is secure against these two attacks. This, however, is no general proof of security. In par- ticular active eavesdropping using, for example, an entangling cloner which has been suggested as an ideal attack for some continuous variable crypto-schemes [17] is not included here and requires further analysis.

To achieve this goal the original message (plain text) is encoded into a coded message known as cipher text. This process of converting from plain text to cipher text is known as enciphering or encryption; restoring the plain text from cipher text is called deciphering or decryption. The central problem in cryptography is the key distribution problem, for which there are essentially two solutions: one based on mathematic laws and one based on physics (Quantum Cryptography). While classical cryptography relies on the computational difficulty of factoring large integers, quantum cryptography relies on the universal laws of quantum mechanics.

ABSTRACT: Cryptography provides security for the information and personal details. Quantum cryptography is an approach to securing communications by applying the phenomena of quantum physics. Quantum cryptography is a new method for secret communications offering the ultimate security assurance of the inviolability of a Law of Nature. Unlike traditional classical cryptography, which uses mathematical techniques to restrict eavesdroppers, quantum cryptography is focused on the physics of information. The combination of 3AQKDP (implicit) and 3AQKDPMA (explicit) quantum cryptography is used to provide authenticated secure communication between sender and receiver. The uses of computer communications networks technologies have increased the incidents of computer abuse. Because of these incidents, most organizations facing pressure to protect their assets. Most digital networks generally rely on modern cryptosystems to secure the confidentiality and integrity of traffic carried across the network. The current modern cryptosystems based on mathematical model introduce potential security holes related to technological progress of computing power, the key refresh rate and key expansion ratio, the most crucial parameters in the security of any cryptographic techniques. For that reason efforts have been made to establish new foundation for cryptography science in the computer communications networks. “I am fairly familiar with all forms of secret writings, and am myself the author of a trifling monograph upon the subject, in which I analyse one hundred and sixty separate ciphers; but I confess that this one is entirely new to me. The object of those who invented the system has apparently been to conceal that these characters convey a message ...”

In this report we discuss the results of our project for the Radboud Honours Academy, concerning Quantum Key Distribution (QKD). We originally started this project with a much larger research subject in mind, namely quantum cryptography and quantum computers. At the beginning of this year, none of us had even heard of quantum cryp- tography. It was professor Klaas Landsman who introduced this as a research subject for the first year of the Honours programme. But after a short time, we felt that narrowing this subject was necessary: we decided to to forget about quantum computers and focus on currently commercially available systems implementing QKD protocols. In particular, our goal was to investigate the business versus the hacking culture. By exploring both the suppliers of quantum cryptographic devices and the people who want to hack these sys- tems, we wanted to get a complete and realistic a picture of the physical implementations of quantum cryptography that are nowadays possible.

Alongside the development and standardization of post-quantum algorithms in the NIST Post- Quantum Cryptography Standardization project, there have been various efforts to begin preparing the TLS ecosystem for post-quantum cryptography. We can see at least three major lines of work: (draft) specifications of how post-quantum algorithms could be integrated into existing protocol formats and message flows [SWZ16, CC19, KK18, WZFGM17, SS17, SFG19]; prototype implementations demonstrating such integrations can be done [Bra16, Lan18a, BCNS15, BCD + 16, Ope19b, Ope19c, KS19, KLS + 19] and whether they would meet existing constraints in protocols and software [CPS19]; and performance evaluations in either basic laboratory network settings [BCNS15, BCD + 16] or more realistic network settings [Bra16, Lan18b, Lan19, KLS + 19, KS19]. This paper focuses on the last of these issues, trying to understand how post-quantum cryptography’s slower computation and larger communication sizes impact the performance of TLS.

M.E Student, Dept of CSE, P. R. Patil college of Engineering and Technology, Amravati, Maharashtra, India Professor, Dept of IT, P. R. Patil college of Engineering and Technology, Amravati, Maharashtra, India. ABSTRACT: Quantum cryptography is an approach toward secure communication by applying the phenomena of quantum physics. As compared to the classical cryptography, quantum cryptography provides more secure communication whose security depends only on the validity of quantum theory. It is an emerging technology in which two parties may simultaneously generate shared, secret cryptographic key material using the transmission of quantum states of light. Quantum cryptography is one of the few commercial applications of quantum physics at the quantum level. The quantum relies on two important elements of quantum mechanics- the Heisenberg uncertainty principle and principle of photon polarization. This paper focuses on the principle of quantum cryptography and how this technology contributes in security of network.

Different quantum cryptographic protocols have different ways of quantum transmission, but they have one thing in common: the principle of quantum mechanics (such as the Heisenberg Uncertainty Principle). In the actual communication system, Alice randomly selects the photon polarization state and the base vector of single photon pulse in the quantum channel and sends it to Bob. Then Bob randomly selects base vectors for measurements. The bit string that is measured is recorded as a codebook. However, the acceptance of information is affected by the presence of noise and Eve. In particular, Eve may use various methods to interfere with and monitor Bob, such as quantum copy, interception, forwarding, etc... According to the Uncertainty Principle, the external interference will lead to the change of the photon polarization state in the quantum channel and affect the measurement results of Bob, so that the behavior of the listeners can be detected and determined. This is also an important feature of quantum cryptography that is distinguished from other cryptosystems. Data Screening

Justin Mullins [23] has focused that, Quantum cryptography solves the problem of key distribution. Cipher text is added with the key .If the receiver knows the key, he (or) she can easily decode the message by subtracting key from the cipher text. Townsend [25] has discussed that depending on link effect, secure QKD results are reduced key rates. The satellite based QKD is feasible of secure key exchange with low earth orbit. Bennett C.H., et al [27] has introduced that, the first QKD protocol and uses two-dimensional quantum systems or qubits as information carriers. A protocol for Coin-tossing by exchange of quantum messages, which is secure against traditional kinds of cheating.

additional passes of classical data transmission. If Eve tries to differentiate between two non-orthogonal states, it is not possible to achieve information gain without collapsing the state of at least one of them . Proofs of the security of quantum cryptography are given variously in References pactical issues have been considered in References, and optical implementations are discussed in References . The issue of using attenuated lasers rather than single photon sources is considered .. In short, quantum cryptography is ideally suited for OBS since it is fundamentally based on the quantum properties of a photon. Besides leading to a theoretically unbreakable encryption scheme, the quantum- based encryption technology is well matched for use in an end-to-end photonic environment, which the OBS environment typifies.

develop these challenges, key management (KM) in the cloud environment will be one of the choices. Efficient KM in random locations where big data being approached to the cloud storage is considered. Even strong security is established by the users, data storage and transmission in cloud environments cannot be controlled by the users without cloud service providers. This challenge is also one of the interesting topics. According to [3], size of the big data has been doubling every 2 years since 2011. Very soon (maybe by 2020), the size of big data will be 2.5 zettabytes (2.5 x 10 21 bytes) of information could be encrypted using quantum cryptography (QC).

Single factor authentication in online banking is no longer sufficient to protect accounts. Our objective is to propose an authentication method for the online banking security. Our proposed model can be seen in figure 4. The starting point is the user’s request. In the event of a request, the user is redirected to authentication service, carrying with him/her some kind of Pass code or PIN. After verifying that pass code or PIN the user will access that Quantum cryptosystem. Quantum Cryptography / Quantum Key Distribution involvement is needed only to authenticate.

The idea was first proposed in the 1970’s but was not applied to information security until the early 1990's. Quantum cryptography is only used to solve the key distribution problem, not actually transmit any useful data. It does so by transmitting photons of light through either fiber optics or free space [2]. These photons of light adhere to the Heisenberg uncertainty principle or quantum entanglement.

Quantum cryptography [7] is an evolving technology that provides safety and security for network communication by performing cryptographic tasks using quantum mechanical effects. Quantum Key Distribution (QKD) is a technique that is an application of quantum cryptography that has gained popularity recently since it overcomes the flaws of conventional cryptography QKD makes the secure distribution of the key among different parties possible by using properties of physics. The quantum states of photons are used and the security key information is transmitted via polarized photons that contain the message denoted by bits (0 or 1) and each photon contains one bit of quantum information called as Qubit. The sender sends the polarized photon to the receiver. At the receiver end, the user determines the photon polarization by passing it through a filter and checks for any modifications in the received bits of photons when compared to the bits measured by the receiver. Any modifications found would show that there has been an intrusion from a third party because the intrusion would irreversibly change the encoded data in the photon of either the sender or the receiver.

We hack a commercial actively-quenched avalanche single-photon detector (PerkinElmer SPCM- AQR) commonly used for quantum cryptography. This study complements the recent hacking of passively-quenched and gated detectors by the same method, and thus demonstrates its generality. Bright illumination is used to blind the detector, such that it exits single-photon detection mode and instead operates as a mere classical photodiode. In this regime, the detector clicks controllably if a bright pulse is applied above a classical sensitivity threshold, allowing for an attack on quantum cryptography that eavesdrops the full secret key. The SPCM-AQR detector model exhibits three redundant blinding mechanisms: (1) overload of an opamp in the bias control circuit, (2) thermal blinding of the APD itself, and (3) overload of the DC/DC converter biasing the APD. This confirms that multiple loopholes may be left open if one does not examine closely non-idealities in components used for quantum cryptography implementations. To reach the security envisioned by theoretical proofs, this practice must change.