Современные информационные технологии/ 1.Компьютерная  инженерия.

Bulatova M.B.

Kostanay State University named after A. Baitursynov, Kazakhstan

Cryptographic means of information protection

Cryptography (or cryptology; from Greek κρυπτός, "hidden, secret"; and γράφειν, graphein, "writing", or -λογία, -logia, "study", respectively) is the practice and study of techniques for secure communication in the presence of third parties (called adversaries). More generally, it is about constructing and analyzing protocols that overcome the influence of adversaries and which are related to various aspects in information security such as data confidentiality, data integrity, authentication, and non-repudiation. Modern cryptography intersects the disciplines of mathematics, computer science, and electrical engineering. Applications of cryptography include ATM cards, computer passwords, and electronic commerce.

Cryptography prior to the modern age was effectively synonymous with encryption, the conversion of information from a readable state to apparent nonsense. The originator of an encrypted message shared the decoding technique needed to recover the original information only with intended recipients, thereby precluding unwanted persons to do the same. Since World War I and the advent of the computer, the methods used to carry out cryptology have become increasingly complex and its application more widespread.

Modern cryptography is heavily based on mathematical theory and computer science practice; cryptographic algorithms are designed around computational hardness assumptions, making such algorithms hard to break in practice by any adversary. It is theoretically possible to break such a system but it is infeasible to do so by any known practical means. These schemes are therefore termed computationally secure; theoretical advances, e.g., improvements in integer factorization algorithms, and faster computing technology require these solutions to be continually adapted. There exist information-theoretically secure schemes that provably cannot be broken even with unlimited computing power—an example is the one-time pad—but these schemes are more difficult to implement than the best theoretically breakable but computationally secure mechanisms.

Information in today's society is one of the most valuable things in life that requires protection against unauthorized access of people not having access to it. Appearance in the mid-twentieth century of the first electronic computer utilities radically changed the situation in the field of encryption ( cryptography ) . The problem of ensuring the necessary level of protection of information proved ( and it is a domain validated by both theoretical studies and practical experience of the decision) to be very complex, requiring for its decision not only implementing a certain set of scientific, technical and organizational measures and the use of specific tools and methods , but creating an integrated system of organizational measures and the use of specific tools and methods for the protection of information. Volume of circulating information in society is steadily increasing .

Popularity of worldwide network Intrenet in recent years contributes to doubling of information every year. In fact, on the eve of the new millennium, humanity has established an informational society in which the well-being and even survival of humanity in its current capacity depends on the successful operation of information processing. Widespread introduction of personal computers has brought the level of "informatization" of business life to a new level . The task of cryptography, i.e. covert communication, is only for information that needs protection . In such cases it’s said that information contains proprietary or protected , private , confidential , secret . For most typical , common cases of this type introduced even special concepts: a state secret ; military secret , trade secret , the secret law , patient confidentiality , etc.

Cryptography - is a set of methods of protection of information interactions from deviations from their normal , regular flow caused by malicious acts of different persons, methods, based on secret algorithms(schemes) of transforming information, including algorithms which are not strictly confidential , but uses covert parameters . Historically, the first task of cryptography was to protect text message from reading their content by unauthorized users, which is reflected in the title of this discipline; this protection is based on the use of "secret language" known only to the addresser and the addressee, all encryption methods are only the development of the philosophical idea. With the increasing complexity of information interactions in human society have emerged and continue to evolve the task of protecting information, some of them have been resolved in the framework of cryptography , which required the development of new approaches and methods.

Cryptographic means of protection are special means and methods of transformation of information as a result of which its content is masked . The main types are closing cryptographic encryption and data encoding. Encryption is a kind of a closure , when the transformation is subjected to each self- closable symbol; data, protected by data encoding, is divided into blocks having the meaning , and each block is replaced with numeric, letter or combined source . It uses several different encryption systems : substitution, permutation , divisive data transformation.

Any modern cryptographic system is based upon the use of cryptographic keys. It works under a specific methodology ( procedure) , consisting of one or more encryption algorithms ( mathematical formulas ); of keys using these encryption algorithms ; key management system , plaintext , and ciphertext. Cryptography today - is the most important part of information systems : from email to cellular network, from access from the Internet to electronic cash .

Nowadays, computer security is a house of cards , which can fall apart at any moment. Too many weak products still were not crashed just because they are little used . Press will immediately give publicity to these attacks , undermining public confidence in these cryptosystems . In the end, the safety of cypherproducts will determine its victory in the market.