During the Cold War, a revolutionary cryptographic method, quantum cryptography, emerged. Grounded in the laws of quantum physics, quantum cryptography ensures absolute security using quantum principles. Stephen Wiesner introduced the concept in 1983, but initially received little attention, as technology at the time did not allow the encryption method to be put into practice. The field of quantum cryptography began to take shape with the arrival of two more researchers, Giles Brassard and Charles Bennett. The development of quantum cryptography accelerated dramatically after Artur Ekert proposed the application of Bell’s theorem in this field. Afterwards, more researchers got involved and new theorems and applications were developed, leading the field to become a major subject at the forefront of physics research. This paper explores why quantum cryptography is exceptionally secure and the steps that brought this idea to practice. The paper looks into the intriguing concept of quantum cryptography and the stimulating stories surrounding its progress. From Stephen Wiesner’s original proposal through Brassard and Bennett’s persistent efforts to the exciting debates between Ekert and Brassard and Bennett. This paper highlights the significant milestones and achievements that have positioned quantum cryptography at the forefront of physics research.
During the Cold War, a revolutionary cryptographic method, quantum cryptography, emerged. Grounded in the laws of quantum physics, quantum cryptography ensures absolute security using quantum principles. Stephen Wiesner introduced the concept in 1983, but initially received little attention, as technology at the time did not allow the encryption method to be put into practice. The field of quantum cryptography began to take shape with the arrival of two more researchers, Giles Brassard and Charles Bennett. The development of quantum cryptography accelerated dramatically after Artur Ekert proposed the application of Bell’s theorem in this field. Afterwards, more researchers got involved and new theorems and applications were developed, leading the field to become a major subject at the forefront of physics research. This paper explores why quantum cryptography is exceptionally secure and the steps that brought this idea to practice. The paper looks into the intriguing concept of quantum cryptography and the stimulating stories surrounding its progress. From Stephen Wiesner’s original proposal through Brassard and Bennett’s persistent efforts to the exciting debates between Ekert and Brassard and Bennett. This paper highlights the significant milestones and achievements that have positioned quantum cryptography at the forefront of physics research.
Quantum cryptography is the only approach to privacy ever proposed that allows two parties (who do not share a long secret key ahead of time) to communicate with provably perfect secrecy under the nose of an eavesdropper endowed with unlimited computational power and whose technology is limited by nothing but the fundamental laws of nature. This essay provides a personal historical perspective on the field. For the sake of liveliness, the style is purposely that of a spontaneous after-dinner speech. It will be seen that the IEEE played a ubiquitous role in this tale. I. PREHISTORY The story begins in the early 1960's, when Stephen Wiesner and Charles Bennett were undergraduates together at Brandeis University. Having many common friends, they enjoyed talking with each other. Later, after Wiesner had gone to grad- uate school at Columbia and Bennett at Harvard, they kept in touch. In particular, the former payed frequent visits to the lat- ter's communal house in Boston. During one of those visits 1 in the late 60's or early 70's 2 , Wiesner told Bennett of his ideas for using mechanics to make banknotes that would be impossible to counterfeit according to the laws of nature, as well as a quantum multiplexing channel, which would allow one party to send two messages to another in a way that the receiving party could decide which message to read but only at the cost of destroying the other message irreversibly. 3
Quantum cryptography is a technology that ensures ultimate security. Compared to current cryptography that could be defeated by by the development of an ultra high-speed computer, quantum cryptography ensures secure communication because it is based on the fundamental physical laws. 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 a new method for secret communications offering the ultimate security assurance of the inviolability of a Law of Nature. The quantum cryptography relies relies on two important elements of quantum mechanics-the Heisenberg Uncertainty principle and the principle of photon polarization. This research paper concentrates on the principle of quantum cryptography, and how this technology contributes to the network security. This paper outlines the real world application implementation of this technology and the future direction in which quantum cryptography accelerates.
Secure data exchange over the network is ensured by the requirements of confidentiality, integrity and availability of information. To meet these requirements, sent data is encrypted on the sending side, and the received information is decrypted on the receiving side. Transmitted message is encrypted according to rules determined by the algorithm and key. Crypto security of encrypted information depends on the key length. Among the encryption algorithms, there are algorithms with a symmetric (private) key and with an asymmetric (public) key. Despite all the advantages of a private key, asymmetric keys are used to deliver it from one user to another (key distribution). However, high-performance quantum computers are capable to decrypt intercepted data. Therefore, modern cryptographic systems use quantum key distribution method. The idea of using quantum bits was proposed in 1970 by S. Wiesner. In 1984, Ch. Bennett and G. Brassard proposed the BB84 protocol. The use of «entangled » quanta for systems with quantum key distribution was offerred in 1991 by A. Eckert. All modern quantum cryptography systems are based on these above-mentioned protocols.
Quantum cryptography is a relatively new field (which began to be developed in 1984), which seems to be taking its last steps to become commercially available, thus becoming the first directly quantum technology to do so. The motivation behind it is not small, since it will allow coding a message in an absolutely secure and illegible way, due to the laws of quantum mechanics, and independently of the power of any computer, even a quantum one. In what seems like a not-too-distant future, engineers who understand and are able to work with such systems will be needed. Therefore, this Master’s Thesis aims to give an introduction to the current development of the field, from the physical concepts that underlie it, to the state of the art of the technology. The text is intended for people with a background in Electrical Engineering, and little or no knowledge of quantum mechanics. However, other readers with a background in engineering or physics will also be able to take advantage of it. After reading it, the reader will be able to have a good starting point in the field, from which to continue developing their work.
Secure communications is a vital need of the world, and the basic features of quantum mechanics seemingly offer fundamental new tools for achieving this security. But do these tools really work? This review gives due attention to the real-world problems with experimental quantum cryptography, but the heart of the review is an in-depth survey of the analyses developed to prove the security of the basic quantum techniques introduced by Wiesner, Ekert, Bennett, and Brassard. A broader set of cryptographic tasks have quantum aspects which are also discussed here.
Cryptography has a long and fascinating history, evolving from ancient techniques to modern methods and now exploring the potential of quantum mechanics. This review paper provides a comprehensive overview of cryptographic techniques from past to present. We begin by examining ancient cryptographic techniques, tracing their origins back to 2000 B.C. when the ancient Egyptians used "secret" hieroglyphics. We also discuss evidence from ancient Greece and Rome, such as secret writings and the famous Caesar cipher [1]. These early methods laid the foundation for the field of cryptography. Next, we delve into modern cryptographic techniques that have become increasingly complex and diverse in their applications. We explore how cryptography now makes extensive use of mathematical concepts from fields like information theory, computational complexity, statistics, combinatorics, abstract algebra, number theory, and finite mathematics. We also discuss how the development of digital computers and electronics has revolutionized cryptography, allowing for the encryption of any kind of binary data and the design of much more intricate ciphers [2]. Finally, we examine the emerging field of quantum cryptography, which aims to harness the principles of quantum mechanics to achieve new cryptographic functionalities beyond classical information alone. We survey some of the most remarkable theoretical uses of quantum information for cryptography, as well as the limitations and challenges faced by cryptographers in this new paradigm [3]. By tracing the evolution of cryptography from ancient times to the present day and beyond, this review paper provides valuable insights into the rich history and promising future of this critical field of study.