Protection of unauthorized copying (copyright) of digital texts using the method of concealing the distance between carrier lines and comparing the position of the key in the text.

Dissertation for Master Degree in Computer Engineering (M.SC)

Trend: Software

Abstract:

Since the beginning of digitization of real and legal documents, the owners of their documents have always been looking for a suitable way to protect their copyright.

The ever-increasing expansion and growth of the Internet has caused extensive changes in the way of life and work activities of individuals, organizations and institutions. Information security is one of the common issues of legal and real persons. Ensuring that unauthorized people do not access sensitive information is one of the most important security challenges related to the distribution of information on the Internet. Sensitive information that we don't want to be viewed and manipulated by others, includes many cases that make up a very large amount, more than 90% of this information is digital texts.

Given the huge amount of textual information in today's world, and its sharing on the Internet, the need to do research in this field is not hidden to anyone, and encryption and cryptography of digital documents as a confidential technique in digital texts, can have many uses. For example, one of the things that has been given serious attention today is to prevent the forgery of electronic documents and the application of the right of the work (copyright) hidden inside the work itself.

In this thesis, a new method to protect the unauthorized copying of digital texts by using message encryption in digital documents such as (MS Word, MS Excel), is presented. comma, dot, comma, double quotation, etc.) in the original text, with subtle changes. Before encryption, the length of the message, which is an 8-bit binary set, is marked in the original text in the form of bit pairs "00, 01, 10, 11" relative to the position of special characters. To do this, four hidden characters (without Unicode length) are considered for each character, in other words, before and after each special character in the text, four pairs of bits are marked with four symbols and

The process will be repeated until all the bits of the message are encrypted in the text.

Key words: information concealment, copyright, encryption, identity verification, manipulation detection.

Chapter One: General Research

Man is bigger than a world and bigger than a collection of worlds. In the union of soul and body, there is a secret more than the secret of the creation of the world.

"Henry Giller"

Introduction

The hiding and encryption of technical data has been of interest to many people for a long time. With the progress of human sciences, the methods of hiding data have been developed in turn with the progress of the used media and techniques of hiding data. Two intervals can be considered for hiding the data. The goal that has been noticed for a long time is the main reason for the emergence of various hiding methods to hide confidential serial data in public media and carriers (Nicolas et al., 1998).

The second goal, which has been published today and is used more often than the goal of fouling, is in the context of the media owner. In the first case, the goal is to include an acceptable amount of data in the media in such a way that the possibility of retrieving them by other people is complicated or impossible. Depending on the type of message and the ways of its transmission, it is usually possible to discover the existence of this week's data in the media, and in any case, it is not acceptable to play the data for other people. In this case, even in cases of data corruption due to media interference, it is not important and even desirable. It is now that in order to reduce the amount of data, they should be somehow hidden from the media to show their resistance against the fearful changes and prevent damage to them.

In the field of data hiding and encryption, there are three concepts that are close to each other. When there is a description of the subject. These three terms mean:

data hiding

data hiding

data encryption

Of the three concepts, the concepts of concealment and conceptual hermeneutics are very close to each other, and separating their fields from each other is complicated. The concept of encryption, despite the fact that it is used to encode data, it can be explained by using other concepts.In the sense that in cryptography, the transmission media has an independent concept of data, it is obvious that they are not data (Hardik Kumar and Pucheri, 2012).

The process of disentangling these three concepts from each other and the field of activity of each will be examined; each of them is a common media encryption technique and uses independent concepts for data transmission, with the existence of all their methods. The data transmitted by the media is clearly accessible, while in the encryption methods, it is not possible to extract the information from its existence. The mentioned method will be shown. In general, it can be said that the above-mentioned two objectives are achieved by their design methods, and scaling is usually used for this purpose (Hardy Kumar and his colleague, 2012).

Definition of Steganography:

Chenography or Steganography is the art and science of communicating secretly and its purpose is to hide the communication by placing the message in a cover medium in such a way that it creates the least detectable change in it and the existence of the hidden message in the medium cannot be revealed easily. The knowledge of covert communication itself includes several branches, including cryptography, cryptography and so on. (Perrooz and Honeyman, 2003).

1-2-1 terms in encryption

In the field of encryption, a number of terms have been developed.

The names masking [4], host [5], embedded [6] and spy [7] are defined in the information hiding workshop in Cambridge. Covering terms refer to the message where other information is placed, such as photo, sound, video and text.

When we use sound in hiding, the signals in which the information is stored are called tables. A query is an information that both overlays contain two nested pieces of information and tell the processing that results in the nesting of the nested pieces of information.

1-2-2-History of steganography

The word steganography [8] is a Greek word meaning invisible writing. The past uses of this technology go back thousands of years.

The first uses are hidden. It was recorded by Herod [9], a historian, and the event was repeated in ancient Greece. According to Darius, he was imprisoned in Susa in the 5th century BC, he had to send a secret message to his brothers in Miletus For this purpose, Muyser Gholamshra sent a message to Farqashar Shakalkobi. When the slave's hair grew to a sufficient size, he went to his destination.

Another legend that has come down from the ancient Greeks is about these kings, the means of writing at that time were tablets that were covered with wax. One of the rulers for information based on the fact that Keshmurd will be appointed, and because this message was found, he cleaned the wax on the boards and posted the text on the board. The wood was carved and then waxed on it again, like the boards that were not used. Then you will not know that you will arrive at the target in the inspections for the material and the problem.

Numerical inks are one of the most common tools for hiding In Rumbastanaz, they used inks like ablimo for writing between the lines. When the texts were edited, the anti-Honmean text was created, the Namir inks were used in the world war of Dominion. 1526, he was a German priest. The first work on cryptography, steganography, which gave explanations about the creation and prediction systems, also in that book, there was also a demand for complex encryption systems. This book was not published in the world, because he was afraid of the revelation of the secret. He wrote a page called Steganographica[14], but most of his works were related to trismus[15], and he was the initiator of the method.

Concealment in the 15th and 16th centuries It developed because most of the authors of these books were afraid of creating division between parties and sects, so they hid their names like stories in the books. One of the thousand years written by Bishop John Wilkin[16] who later became a professor at Trinity College[17]. He proposed some methods of encoding messages in music and non-material essences. Also, the first designs of decryption were made using the repetition of words. One of its examples goes back to the beginning of the century by Manjungboer[18]. Paul Robert Baden[19] proved the location of the enemy instead of drawing it in the shape of a butterfly in the usual way, until it was captured, we did not understand anything about it (Polimnia et al., 1992).

During the Second World War, much attention was paid to concealment, and this experiment was achieved.