We present new physical bounds on quantum information, and use them to prove the security of quantum cryptography against a large class of collective attacks. Such attacks are directed against the final key, and security against them suggests that quantum cryptography is ultimately secure.

Authentication is an indispensable part of Quantum Cryptography, which is an unconditionally secure key distribution technique based on the laws of nature. Without proper authentication, Quantum Cryptography is vulnerable to “man-in-the-middle” attacks. Therefore, to guarantee unconditional security of any Quantum Cryptographic protocols, the authentication used must also be unconditionally sec...

Quantum cryptography is a new method for secret communications offering the ultimate security assurance of the inviolability of a Law of Nature. In this paper we shall describe the theory of quantum cryptography, its potential relevance and the development of a prototype system at Los Alamos, which utilises the phenomenon of single-photon interference to perform quantum cryptography over an opt...

Quantum cryptography could well be the first application of quantum mechanics at the single-quantum level. The rapid progress in both theory and experiment in recent years is reviewed, with emphasis on open questions and technological issues. CONTENTS I. Introduction 145 II. A Beautiful Idea 146 A. The intuition 146 B. Classical cryptography 147 1. Asymmetrical (public-key) cryptosystems 147 2....

Classical digital cryptography is concerned with the problem of providing secure and secret communication over a medium which guarantees neither of these functions. This provision is achieved through the encryption of data at the sender, and the decryption of that cyphertext at the receiver (an encrypted message is known in cryptography as the cyphertext of the message). There are further consi...

We show concept of BB84 quantum key distribution (QKD) protocol and analyze its use as an information system. The difference between classical and quantum cryptography is presented in a way of understanding the main advantage of quantum information processing over classical information processing. At the end of the article, we present today and future use of quantum cryptography and possible im...

Quantum cryptography makes use of the quantum-mechanical behavior of nature for the design and analysis of cryptographic schemes. Optimally (but not always), quantum cryptography allows for the design of cryptographic schemes whose security is guaranteed solely by the laws of nature. This is in sharp contrast to standard cryptographic schemes, which can be broken in principle, i.e., when given ...