The order of designation of project documentation (code). Registration of the course work code List of documents on the basis of which the system is created, by whom and when these documents were approved

Construction of the document.

1. Course work is completed on A4 sheets with mechanical engineering frames.

2. Each sheet must have a frame, a main inscription and additional columns of the main inscription. The first sheet is the title page, the second sheet “Contents” is issued with a 40 mm stamp, subsequent sheets with a 15 mm stamp.

3. The text is written in Times New Roman font, 14, line spacing is single.

4. The distance from the frame to the text borders at the beginning and end of the lines must be at least 3 mm. The distance from the top and bottom lines of text to the top or bottom frame must be at least 10 mm. Paragraphs in the text begin with an indent of 12.5 mm.

5. Typos, clerical errors and graphic inaccuracies may be corrected by carefully erasing or painting with white paint and applying corrections in the same place of the corrected text.

6. The distance between the title and the text is 3-4 line spacing; There are 2 spaces between section and subsection headings.

7. The contents are placed on the first sheet of the document, including the numbers and names of sections and subsections indicating page numbers. The word “Contents” is written in the form of a title (symmetrically to the text) with a capital letter. Names included in the contents are written in lowercase letters, starting with capital letters.

8. At the end of the text document there is a list of literature that was used in its preparation.

9. The numbering of pages of the document and annexes included in this document must be continuous. The first page is the title page (title page).

Design of tables.

1. Tables are used for clarity and convenience of comparison of numerical values ​​of indicators.

2. The table title line is separated from the main part of the table by a double line. On the left above the table the word “Table” is placed, highlighted by a space. After it they put the table number, but do not put a dot after the table number.

3. If necessary, give the name of the table, which is written with a capital letter after its number, separated by a hyphen. In this case, there is no dot after the name.

Example: Table 1 - Product Specifications

4. Tables are numbered with Arabic numerals and continuous numbering throughout the entire text, with the exception of appendix tables.

Design of drawings.

1. You can place illustrations in a text document.

2. All illustrations are called drawings and numbered in Arabic numerals with continuous numbering throughout the document or within a section.

3. Illustrations are positioned so that they can be read without rotating the document or after rotating it 90 degrees clockwise.

4. The illustration, if necessary, may have a name and explanatory data (text below the figure). The word “Figure” and the name are placed after the explanatory data.

Example: Figure 1 – Device details

Design of literature.

1. Bibliographic information is placed at the end of the text document under the heading “Bibliography” before all appendices.

2. In the text of the explanatory note, information about sources should be arranged in the order in which references to sources appear and numbered in Arabic numerals in square brackets, indicating the serial number of the document according to the list of sources of literature, as well as, if necessary, pages, for example: .

The compilation and formatting of the bibliography should be done in alphabetical order by the authors' surnames or titles (if the author is not indicated). It is not allowed to mix different alphabets in one list. Foreign literature must be listed at the end of the list of references in the language of publication. The description of electronic sources is part of the entire list of references.

Anokhin I. T. Fundamentals of financial management: textbook. allowance / I. T. Anokhin. - 3rd ed., revised. and additional - M.: Finance and Statistics, 2000. - 528 p.

Shostak A. D. Enterprise finance / A. D. Shostak, R. S. Sinyaev. - M.: INFRA, 1999. - 343 p.

Tax policy of Russia: problems and prospects / I. V. Novikov et al. - M.: Finance and Statistics, 2003. - 287 p.

d) standards:

GOST R 517721 - 2001. Household radio-electronic equipment. Input and output parameters and connection types. Technical requirements. - Vved, 2002-01-01. - M.: Publishing house of standards, 2001. - IV, 27 p.

e) book (Internet):

Palkov I. A. Financial models [Electron, resource]: lecture notes and test work for correspondence students. forms of training / I. A. Palkov. - Omsk, 2002. - Access mode: http//195.162.33.166/fulltext/ED107.doc

f) description of electronic resources:

Rodnin A. N. Logistics [Electron, resource]: terminologist. Dictionary: "Code-CD" / A. N. Rodnin. - M.: INFRA; M.: Thermika, 2001.-1 el. wholesale disk (CD-ROM).

Formulation of course work code.

AAAA.BCCDEE.FFFGG

AAAA – department code (ENiOPD - 2403)

B - nature of work code

1 – thesis

2 – course project

3 – course work

5 – laboratory work

CC – discipline code (according to a separate list, computer science - 02)

D – topic number (0 for all)

EE – option number (number according to the group journal)

FFF – serial registration number (000)

GG – type of document (PZ – explanatory note)

Manitsyn Alexander

Research work of an 8th grade student within the framework of a scientific and practical conference of students. The work conducts a study of the existing simplest ciphers, the history of the origin of ciphers, and attempts are made to create your own cipher.

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Municipal budgetary educational institution

Secondary school No. 1.

Educational and research work

"Mathematics and Ciphers"

Department: Physics and Mathematics

Section: mathematics

Completed:

student of class 7 "A"

Manitsyn Alexander

Supervisor:

mathematic teacher

Lefanova N. A.

Pavlovo

2012

Introduction…………………………………………………………………….3

Literature review……………………………………………………..4

1. Theoretical part…………………………………………………………….5

1. .History of the development of ciphers and cryptography………………….5
2. Types of ciphers……………………………………………………7
3. The most mysterious ciphers……………………………………15

1. Practical part…………………………………………………………….. 16
2. Applications………………………………………………………18

Conclusion…………………………………………………………….19

Used literature………………………………………………………20

Introduction

Cipher – some kind of text conversion system with a secret to ensure the secrecy of transmitted information. Cryptography is one of the oldest sciences that studies ciphers. The problem of protecting information by transforming it to prevent it from being read by unauthorized persons has worried the human mind since ancient times. As soon as people learned to write, they immediately had a desire to make what was written understandable not to everyone, but only to a narrow circle of people. Even in the most ancient written monuments, scientists find signs of deliberate distortion of texts.

In modern times, ciphers are used for secret correspondence between diplomatic representatives and their governments, in the armed forces for transmitting the text of secret documents via technical means of communication, by banks to ensure the security of transactions, and also by some Internet services for various reasons.

Cryptography, namely methods of encrypting and decrypting information, aroused my great interest. The ability to transform text so that no one understands what you read but you is very exciting. That is why I chose such a complex, but on the other hand, interesting topic for me.

In the documents of ancient civilizations - India, Egypt, Mesopotamia, there is information about systems and methods for composing encrypted letters. Cryptography received its greatest development at this time in the policies of Ancient Greece, and later in Rome. So, the most common and widely known replacement cipher in the ancient world is the CAESAR CIPHER, I will talk about this later...

Goal of the work.

1. Study the origin and history of the development of cryptography and ciphers.

2. Explore the types of ciphers, their descriptions and keys (solution).

3.Practise encryption.

4. Identify the most mysterious ciphers and talk about them.

5.Draw conclusions.

Literature review

1. Gatchin Yu.A., Korobeinikov A.G. "Fundamentals of Cryptographic Algorithms". Tutorial. St. Petersburg State University of Information Technologies, Mechanics and Optics, 2002.

The textbook examines the basics of modern mathematical cryptographic algorithms, the foundation of which is applied number theory. Cryptosystems with a secret key (single-key, symmetric or classical), as well as cryptosystems with an open key, are considered.
key (asymmetrical).

2. Zubov A.Yu. "Perfect Ciphers". Helios ARV 2003.

The properties and designs of unconditionally strong ciphers, called by K. Shannon perfect in relation to various crypto-attacks, are outlined. Perfect ciphers with the minimum possible number of keys are identified, as well as those that are resistant to attempts at deception by an attacker.

3. Simon Singh "Code Book".AST, Astrel 2007.

The “Book of Codes” contains many interesting facts from history. After all, there were wars in which the one who knew more won, there were secrets that had to be carefully hidden from prying eyes, there was encrypted information on which people’s lives depended. And in our time, the importance of information is difficult to overestimate. And mathematics, in particular number theory, has always played an important role in the development of cryptography.

Simon Singh talks about the constant battle waged by cryptographers and codebreakers, the different encryption methods that have ever been used, and the methods of decryption. He also talks about the people who developed cryptography and the challenges that cryptographers face today. The book presents the history of encryption, talks about permutation ciphers, substitution ciphers, and public key encryption. There are also problems that you can solve on your own and feel like a codebreaker working on the text.

1. Theoretical part

1. History of the development of ciphers and cryptography.

The history of cryptography goes back about 4 thousand years. There is evidence that cryptography as a text security technique arose along with writing, and methods of secret writing were already known to the ancient civilizations of India, Egypt and Mesopotamia.

The first mention of the use of cryptography is considered to be the use of special hieroglyphs about 3900 years ago in Ancient Egypt. Although the goal was not to make the text difficult to read - rather, on the contrary, to attract the reader’s attention with the help of unusualness and mystery and glorify the nobleman Khnumhotep the Second. Subsequently, there are various references to the use of cryptography, most of which relate to military use.

The first period (from approximately the 3rd millennium BC) is characterized by the dominance of mono-alphabetic ciphers (the basic principle is the replacement of the original text alphabet with another alphabet by replacing letters with other letters or symbols).

The second period (chronological framework - from the 9th century in the Middle East and from the 15th century in Europe to the beginning of the 20th century) was marked by the introduction of polyalphabetic ciphers into use.

The third period (from the beginning to the middle of the 20th century) is characterized by the introduction of electromechanical devices into the work of cryptographers. At the same time, the use of polyalphabetic ciphers continued.

The fourth period, from the mid-20th century to the 70s of the 20th century, is the period of transition to mathematical cryptography. In Shannon's work, strict mathematical definitions of the amount of information, data transfer, entropy, and encryption functions appear. A mandatory step in creating a cipher is to study its vulnerability to various attacks. However, until 1975, cryptography remained “classical”, or, more correctly, secret key cryptography.

The modern period of development of cryptography (from the late 1970s to the present) is distinguished by the emergence and development of a new direction - public key cryptography. Its appearance is marked not only by new technical capabilities, but also by the relatively wide spread of cryptography for use by individuals. Modern cryptography forms a separate scientific direction at the intersection of mathematics and computer science - works in this area are published in scientific journals, and regular conferences are organized. The practical application of cryptography has become an integral part of the life of modern society - it is used in such industries as e-commerce, electronic document management, telecommunications and others.

1. Types of ciphers

Ciphers can use one key for encryption and decryption, or two different keys. On this basis they distinguish:

2.1. Symmetric ciphers– an encryption method in which the same cryptographic key is used for encryption and decryption.

Data encryption and decryption algorithms are widely used in computer technology in systems for hiding commercial information from malicious use by third parties. The main principle in them is the condition that the transmitter and receiver know in advance the encryption algorithm, as well as the key to the message, without which the information is just a set of symbols that have no meaning.

Classic examples of such algorithms are:

Simple rearrangement.

Simple permutation without a key is one of the simplest encryption methods. The message is written into a table in columns. To use this cipher, the sender and recipient need to agree on a shared key in the form of a table size.

Single permutation by key.

A more practical encryption method called single key permutation is very similar to the previous one. It differs only in that the table columns are rearranged according to a keyword, phrase or set of numbers the length of a table line.

Double permutation.

For added security, you can re-encrypt a message that has already been encrypted. This method is known as double permutation. To do this, the size of the second table is selected so that the lengths of its rows and columns are different than in the first table. It is best if they are relatively prime. In addition, the columns in the first table can be rearranged, and the rows in the second table.

Permutation "Magic Square".

Magic squares are square tables with consecutive natural numbers from 1 inscribed in their cells, which add up to the same number for each column, each row and each diagonal. Such squares were widely used to enter encrypted text according to the numbering given in them. If you then write out the contents of the table line by line, you get encryption by rearranging the letters. At first glance, it seems as if there are very few magic squares. However, their number increases very quickly as the size of the square increases. Thus, there is only one magic square measuring 3 x 3, if you do not take into account its rotations. There are already 880 magic squares of 4 x 4, and the number of magic squares of size 5 x 5 is about 250,000. Therefore, large magic squares could be a good basis for a reliable encryption system of that time, because manually trying all the key options for this cipher was unthinkable.

Numbers from 1 to 16 fit into a square measuring 4 by 4. Its magic was that the sum of the numbers in rows, columns and full diagonals was equal to the same number - 34. These squares first appeared in China, where they were assigned some "magic power".

Magic square encryption was carried out as follows. For example, you need to encrypt the phrase:

“I’m coming today.” The letters of this phrase are written sequentially into the square according to the numbers written in them: the position of the letter in the sentence corresponds to the ordinal number.

A dot is placed in empty cells. After this, the ciphertext is written into a string (reading is done from left to right, line by line):
.irdzegu SzhaoyanP
When decrypted, the text is fit into a square, and the plaintext is read in the sequence of numbers of the “magic square”. The program should generate “magic squares” and select the required one based on the key. The square is larger than 3x3.

Advantages:

· speed;

· ease of implementation;

· smaller required key length for comparable durability;

· knowledge.

Flaws:

Difficulty in key exchange. To use it, it is necessary to solve the problem of reliable transfer of keys to each subscriber, since a secret channel is needed to transfer each key to both parties.

2.2. Asymmetric encryption– an encryption system in which the public key is transmitted over an open (that is, unprotected, observable) channel, and is used to verify the digital signature and to encrypt the message. A secret key is used to encrypt and decrypt the message. Public key cryptographic systems are now widely used in various network protocols.

Although the key pair is mathematically related, calculating the private key from the public key is not practical. Anyone who has your public key will be able to encrypt the data, but will not be able to decrypt it. Only a person with the corresponding private key can decrypt the information. Therefore, public key cryptography uses one-way functions with a backdoor. A loophole is a kind of secret that helps to decipher. For example, if you disassemble a watch into many components, it is very difficult to reassemble the watch again. But if there is an assembly instruction (loophole), then this problem can be easily solved.

For example:

A scheme is being considered with the ability to restore the original message using a “loophole,” that is, hard-to-access information. To encrypt text, you can take a large subscriber directory, consisting of several thick volumes (it is very easy to find the number of any city resident using it, but it is almost impossible to find a subscriber using a known number). For each letter from the encrypted message, a name starting with the same letter is selected. Thus, the letter is assigned to the subscriber's telephone number. The message being sent, for example "BOX", will be encrypted as follows:

The cryptotext will be a chain of numbers recorded in the order of their selection in the directory. To make decoding more difficult, you should

choose random names starting with the desired letter. Thus, the original message can be encrypted by many different lists of numbers.

System Features:

· The advantage of asymmetric ciphers over symmetric ciphers is that there is no need to first transmit the secret key over a reliable channel;

· In symmetric cryptography the key is kept secret for both parties, but in an asymmetric cryptosystem there is only one secret key;

· With symmetric encryption, it is necessary to update the key after each transmission, whereas in asymmetric cryptosystems the pair can not be changed for a considerable time.

Flaws:

· The advantage of a symmetric encryption algorithm over an asymmetric one is that it is relatively easy to make changes to the first one;

· Although the messages are securely encrypted, the recipient and the sender are “exposed” by the very fact of sending an encrypted message;

· Asymmetric algorithms use longer keys than symmetric ones.

Ciphers can be designed to either encrypt all text at once or encrypt it as it is received. Thus there are:

A block cipher encrypts an entire block of text at once, releasing the ciphertext after receiving all the information;

A stream cipher encrypts information and produces ciphertext as it arrives, thus being able to process text of unlimited size using a fixed amount of memory.

There are also substitution ciphers that are not currently used, and for the most part have weak cryptographic strength.

2.3. Block cipher

A block cipher is a type of symmetric cipher. A special feature of a block cipher is that it processes a block of several bytes in one iteration (repetition). Block cryptosystems break the text of a message into individual blocks and then transform these blocks using a key.

The conversion should use the following principles:

· Scattering – that is, changing any plaintext character or key affects a large number of ciphertext characters, which hides the statistical properties of the plaintext;

· Shuffle – the use of transformations that make it difficult to obtain statistical dependencies between the ciphertext and the plaintext.

Block cipher operating modes.

The simplest mode of operation of a block cipher is ECB (Fig. 1), where all plaintext blocks are encrypted independently of each other. However, when using this mode, the statistical properties of open data are partially preserved, since each identical data block uniquely corresponds to an encrypted data block. If there is a large amount of data (for example, video or audio), this can lead to leakage of information about its content and provide greater scope for cryptanalysis.

2.4. Stream cipher

A stream cipher is a symmetric cipher in which each plaintext character is converted into a ciphertext character depending not only on the key used, but also on its location in the plaintext stream.

Classification of stream ciphers:

Let us assume, for example, that in the gamma mode for stream ciphers, during transmission over a communication channel, one ciphertext character was distorted. Obviously, in this case, all characters received without distortion will be deciphered correctly. Only one character of text will be lost. Now imagine that one of the ciphertext characters was lost during transmission over the communication channel. This will cause all text following the missing character to be incorrectly decrypted.

Almost all data transmission channels for stream encryption systems contain interference. Therefore, to prevent information loss, they solve the problem of synchronizing text encryption and decryption. According to the method of solving this problem, cipher systems are divided into synchronous and self-synchronizing systems.

Synchronous stream ciphers

Synchronous stream ciphers (SSC) are ciphers in which the key stream is generated independently of the plaintext and ciphertext.

During encryption, the keystream generator produces keystream bits that are identical to the keystream bits during decryption. Losing a ciphertext sign will result in the synchronization between the two generators being out of sync and the rest of the message being unable to be decrypted. Obviously, in this situation, the sender and recipient must re-sync to continue.

Typically, synchronization is performed by inserting special markers into the transmitted message. As a result, a character missed during transmission leads to incorrect decryption only until one of the tokens is received.

Note that synchronization must be performed such that no part of the key stream is repeated. Therefore, it makes no sense to transfer the generator to an earlier state.

Pros of SPS:

· no effect of error propagation (only the distorted bit will be decrypted incorrectly);

· protect against any insertions and deletions of ciphertext, as they will lead to loss of synchronization and will be detected.

Disadvantages of SPS:

· Vulnerable to changing individual bits of the ciphertext. If an attacker knows the plaintext, he can change these bits so that they are decrypted as he wants.

Self-synchronizing stream ciphers

Self-synchronizing stream ciphers or asynchronous stream ciphers (ASC) are ciphers in which a key stream is created by a function of a key and a fixed number of ciphertext characters.

So, the internal state of the keystream generator is a function of the previous N bits of the ciphertext. Therefore, the decrypting key stream generator, having received N bits, is automatically synchronized with the encryption generator.

This mode is implemented as follows: each message begins with a random header of N bits long; the header is encrypted, transmitted and decrypted; the decryption is incorrect, but after these N bits both generators will be synchronized.

Pros of APS:

· Shuffle plaintext statistics, because each character of the plaintext affects the next ciphertext. The statistical properties of the plaintext apply to the entire ciphertext. Therefore, APS may be more resistant to plaintext redundancy attacks than PSA.

Disadvantages of APSH:

· error propagation;

· sensitive to opening by retransmission.

2.5.Caesar Cipher

The Caesar cipher is one of the oldest ciphers. When encrypting, each character is replaced by another, spaced from it in the alphabet by a fixed number of positions. The Caesar cipher can be classified as a substitution cipher, or a simple substitution cipher.

The cipher is named after the Roman emperor Gaius Julius Caesar, who used it for secret correspondence. A natural development of the Caesar cipher was the Vigenère cipher. From the point of view of modern cryptanalysis, the Caesar cipher does not have acceptable strength.

1. The most mysterious ciphers

Despite the development of decryption technologies, the best minds on the planet continue to puzzle over unsolved messages. Below are 4 ciphers, the contents of which have not yet been revealed:

1.The most important encrypted message of the ancient culture of the island of Crete was Phaistos disc (Fig. 2) is a clay product found in the city of Fest in 1903. Both sides are covered with hieroglyphs written in a spiral. Experts were able to distinguish 45 types of signs, but only a few of them were identified as hieroglyphs that were used in the pre-palatial period of the ancient history of Crete.

2. Kryptos (Fig. 3) is a sculpture that American sculptor James Sanborn installed in 1990 in Langley. The encrypted message written on it still cannot be deciphered.

3. Bale cryptograms(Fig. 4) - three encrypted messages that are believed to contain information about the location of a treasure buried in the 1820s by a party of gold miners led by Thomas Jefferson Bale.

One of the messages has been deciphered - it describes the treasure itself and gives general indications of its location. The remaining undiscovered letters may contain the exact location of the bookmark and a list of owners of the treasure.

4.Dorabella cipher (Fig. 5), composed in 1897 by the British composer Sir Edward William Elgar. He sent a letter in encrypted form to the city of Wolverhampton to his friend Dora Penny. This code remains unsolved.

1. Practical part

1. Application of one of the mathematical methods

using the example of the Caesar cipher

Encryption using key k = 3. The letter "C" is "shifted" three letters forward and becomes the letter "F". The hard character moved three letters forward becomes the letter "E", and so on:

Original alphabet:

ABVGDEYZHZIYKLMNOPRSTUFHTSCHSHSHSHYYYYUYA

Encrypted: WHERE?

Original text:

If you put it off for a day, it will last for ten.

Ciphertext is obtained by replacing each letter of the original text with the corresponding letter of the cipher alphabet:

Skhosilyya rg zzrya – rg efz zhzfvhya kkhvrzkhfv.

Application of one of the mathematical methods using the example of an Asymmetric Cipher

The following example helps to understand the ideas and methods of public key cryptography: storing passwords on a computer. Each user on the network has their own password. When logging in, he indicates a name and enters a secret password. But if you store a password on a computer disk, then someone can read it (this is especially easy for the administrator of this computer) and gain access to secret information. To solve the problem, a one-way function is used. When creating a secret password, it is not the password itself that is stored on the computer, but the result of calculating a function of this password and user name. For example, the user Alexander came up with the password “Computer”. When saving this data, the result of the function f (COMPUTER) is calculated, let the result be the string PHONE, which will be saved in the system. As a result, the password file will look like this:

Name f (password)

Alexander TELEPHONE

Login now looks like this:

Name: Alexander

Password: COMPUTER

When Alexander enters the "secret" password, the computer checks whether or not the function applied to PHONE gives the correct result COMPUTER, stored on the computer's disk. It is worth changing at least one letter in the name or password, and the result of the function will be completely different. The “secret” password is not stored on the computer in any form. The password file can now be viewed by other users without losing its privacy, since the function is practically irreversible.

1. Application

Figure1 Figure2 1

Original image Cryptogram in ESV mode

Figure 3 Figure 4

Figure 5 Figure 6

Conclusion

A cipher is a set of reversible transformations of a set of open data into a set of encrypted data. The most important components of any cipher are the general rule by which the original text is converted. Through this work I learned about the connection between ciphers and mathematics. And that using various mathematical methods you can encrypt information.

I believe that ciphers are one of the most interesting and relevant topics. Ciphers have been used, are used and will be used because... they are necessary in many areas and help people solve certain logical problems. Encryption is constantly being revealed to society because... systems have been created that are more progressive than previous ones and allow solving serious problems.

Bibliography

1. http://ru.wikipedia.org

2. http://citforum.ru/security/cryptography/yaschenko/78.html

3. http://www.wikiznanie.ru/ru-wz/index.php/Cipher

4. Gatchin Yu.A., Korobeinikov A.G. "Fundamentals of Cryptographic Algorithms". Tutorial. St. Petersburg State University of Information Technologies, Mechanics and Optics, 2002.

5. Zubov A.Yu. "Perfect Ciphers".Helios ARV 2003.

How to assign a “GOST code” to a document

Mikhail Ostrogorsky, 2010

Why do we need document symbols?

We are sometimes asked how to correctly assign a code, code, number, etc. to a document. Let's say right away that this is not a great science. But, firstly, it is not a code or a cipher, but a designation, in any case, if we intend to comply with the ESPD (GOST 19) or KSAS (GOST 34). Secondly, let's first understand what the meaning of document notations is.

In typewritten and paper times, document designations served to maintain an archive. Imagine a large organization that orders or develops many programs or automated systems in-house. She also accumulates a lot of technical documentation. To navigate it, among other things, you need to provide each document with a unique identifier. As such, domestic standards propose to use the designation formed according to certain regular rules. We will talk about them.

Document designations are needed not by the prosecutor, not by Rostekhregulirovanie, not by the program or system developer, but, first of all, by the customer. If your customer demands at all costs that the documents created for him be provided with a “GOST code,” you can respond by asking whether he maintains an archive of technical documentation. Unfortunately, in most cases the answer is no. If the customer has such an archive, then most likely it will be electronic rather than paper. In electronic archives, unique identifiers are usually assigned to documents automatically.

Thus, assigning official designations to documents today is largely meaningless and represents a “magic ritual.” What if the customer still insists on its implementation? Of course, do it.

Designations of documents on automated systems

The structure of the system document designation in accordance with GOST 34.201-89 is shown below. Explanation of parts of the designation is given in the table.

A.B.CCC.DD.EE.F-G.M

As an example, we will assign the designation of technological instructions for the user of this site. We will consider the site as an automated system that we developed for ourselves, and this was our first experience in developing systems of this type. We will consider the user to be an employee of Philosoft who publishes articles on the site. Let us also agree that the person responsible for publication is not the only functional role. We also have a person responsible for placing advertising banners, for whom his own technological instructions have been written. The first edition of the technological instructions is valid, the document is not divided into parts, it exists in the form of a paper original with signatures and seals. Taking into account the above circumstances, the designation is as follows:

63755082.425750.001.I2.01, Where

63755082 - code of Philosoft LLC according to OKPO.

425750 - line code Software and hardware systems for automating information processing in trade, logistics in accordance with OKP. The author of the article looked through the OKP, thought and decided that this characteristic suits our site better than all the others offered there. Perhaps he is mistaken.

001 is the registration number of an automated system of this type in our internal records (let’s assume that we keep it).

I2 - code of technological instructions according to GOST 34.201-89.

01 - number of technological instructions in the set of technical documentation for the site. Let us remind you that there is another one for the manager of advertising banners, its number is 02.

Designation of technical specifications for an automated system

In clause 3.2 of GOST 34.602-89 there is a phrase that mentions a certain TK code: “Sheet (page) numbers are placed starting from the first sheet, following the title page, at the top of the sheet (above the text, in the middle) after indicating the TK code on the AC.” At the same time, GOST 34.201-89 provides codes for documents developed at stages starting from the preliminary design, but there is no code for technical specifications, which is somewhat confusing.

When generating the technical specification code for the speakers, you can take into account clause 3.5. GOST 34.602-89, which says: “If necessary, codes established in the industry may be placed on the title page of the technical specifications for the AS, for example: security classification, work code, registration number of technical specifications, etc.,” and assign the code arbitrarily, citing the fact that this is customary in the industry or determined by the scientific and technical documentation of a particular enterprise. In addition, you can remember that according to GOST 24.101-80 the technical specification had code 2A, and assign the document a designation according to the scheme described above. But in general, this all already resembles a scholastic calculation of the number of devils on the tip of a needle.

Program document symbols

The designation structure of a program document in accordance with GOST 19.103-77 is shown below. Explanation of parts of the designation is given in the table. The revision number, document number and document part number are formed in the same way as for system documents (from a historical perspective it’s the other way around, but we ask the reader to forgive us for this anachronism).

A.B.CCCCC-DD EE FF-G

The initial part of the designation, A.B.CCCC-DD, serves as a designation for the program itself and at the same time for the main document associated with it, the specification.

Design document designations

Any program or automated system can be considered as a product and documented on a general basis, guided by ESKD (GOST 2). The same series of standards should be used when documenting technical means, such as servers, workstations, all kinds of specialized devices, etc. The rules for assigning designations to design documents are established by GOST 2.201-80. Here we will refrain from retelling this document, but we have no doubt that now the reader will easily find and master it.

Approval Sheet Designations

If the document is provided with an approval sheet, the latter must have its own designation. It is formed according to an elementary rule: a code should be added to the document designation LU, separated by a hyphen, for example: 63755082.425750.001.I2.01-LU.

On the usefulness of notation with cautious optimism

An attentive reader has noticed that if all organizations carefully adhered to such rules, document designations would be unique within the country. Then it would be possible, say, to establish a national catalog of technical documentation, through which any engineer could request the document he needs. This would probably facilitate the integration of automated systems of different departments, but today we are experiencing a lot of all sorts of bureaucratic inconveniences precisely because of their isolation. For example, pensioners are forced to take a certificate from the registry office that they are still alive and personally deliver it to Social Security, only then they are given all sorts of allowances and benefits. The question arises: why shouldn’t the automated systems of the Civil Registry Office and Social Security work with a single array of data? On the other hand, the experienced reader will notice that these arguments are sinning with utopianism, and he will be right.

It is possible that document designations can still be useful today in the development and approval of large sets of technical documentation. In correspondence among themselves and in various work materials, project participants often have to make references to documents, list them, or mention them in different contexts. When the number of documents in a project increases, it becomes inconvenient to refer to them by name. During the course of a project, names may be subject to edits; in addition, people often indicate them from memory, abbreviating them and making mistakes, which naturally leads to confusion. For example, a customer reports an error in one document, but the developer does not understand it and makes unnecessary corrections to another with a similar name. It is hoped that the use of notations will help get rid of such troubles.

The need to encrypt correspondence arose in the ancient world, and simple replacement ciphers appeared. Encrypted messages determined the fate of many battles and influenced the course of history. Over time, people invented more and more advanced encryption methods.

Code and cipher are, by the way, different concepts. The first means replacing every word in the message with a code word. The second is to encrypt each symbol of information using a specific algorithm.

After mathematics began to encode information and the theory of cryptography was developed, scientists discovered many useful properties of this applied science. For example, decoding algorithms have helped decipher dead languages ​​such as ancient Egyptian or Latin.

Steganography

Steganography is older than coding and encryption. This art appeared a long time ago. It literally means “hidden writing” or “secret writing.” Although steganography does not exactly correspond to the definition of a code or cipher, it is intended to hide information from prying eyes.

Steganography is the simplest cipher. Typical examples are swallowed notes covered with wax, or a message on a shaved head that is hidden under the growth of hair. The clearest example of steganography is the method described in many English (and not only) detective books, when messages are transmitted through a newspaper where letters are discreetly marked.

The main disadvantage of steganography is that an attentive outsider can notice it. Therefore, to prevent the secret message from being easily read, encryption and encoding methods are used in conjunction with steganography.

ROT1 and Caesar cipher

The name of this cipher is ROTate 1 letter forward, and it is known to many schoolchildren. It is a simple substitution cipher. Its essence is that each letter is encrypted by shifting the alphabet 1 letter forward. A -> B, B -> B, ..., I -> A. For example, let’s encrypt the phrase “our Nastya is crying loudly” and get “obshb Obtua dspnlp rmbsheu”.

The ROT1 cipher can be generalized to an arbitrary number of offsets, then it is called ROTN, where N is the number by which the encryption of letters should be offset. In this form, the cipher has been known since ancient times and is called the “Caesar cipher.”

The Caesar cipher is very simple and fast, but it is a simple single permutation cipher and is therefore easy to break. Having a similar drawback, it is only suitable for children's pranks.

Transposition or permutation ciphers

These types of simple permutation ciphers are more serious and have been actively used not so long ago. During the American Civil War and World War I it was used to transmit messages. Its algorithm consists of rearranging the letters - write the message in reverse order or rearrange the letters in pairs. For example, let’s encrypt the phrase “Morse code is also a cipher” -> “Akubza ezrom - ezhot rfish”.

With a good algorithm that determined arbitrary permutations for each symbol or group of them, the cipher became resistant to simple cracking. But! Only in due time. Since the cipher can be easily cracked by simple brute force or dictionary matching, today any smartphone can decipher it. Therefore, with the advent of computers, this cipher also became a children's code.

Morse code

The alphabet is a means of exchanging information and its main task is to make messages simpler and more understandable for transmission. Although this is contrary to what encryption is intended for. Nevertheless, it works like the simplest ciphers. In the Morse system, each letter, number and punctuation mark has its own code, made up of a group of dashes and dots. When transmitting a message using the telegraph, dashes and dots represent long and short signals.

The telegraph and alphabet was the one who was the first to patent “his” invention in 1840, although similar devices had been invented before him in both Russia and England. But who cares now... The telegraph and Morse code had a very great influence on the world, allowing almost instantaneous transmission of messages over continental distances.

Monoalphabetic substitution

ROTN and Morse code described above are representatives of monoalphabetic replacement fonts. The prefix "mono" means that during encryption, each letter of the original message is replaced by another letter or code from a single encryption alphabet.

Deciphering simple substitution ciphers is not difficult, and this is their main drawback. They can be solved by simple search or frequency analysis. For example, it is known that the most used letters in the Russian language are “o”, “a”, “i”. Thus, we can assume that in the ciphertext, the letters that appear most often mean either “o”, “a”, or “i”. Based on these considerations, the message can be deciphered even without computer search.

Mary I, Queen of Scots from 1561 to 1567, is known to have used a very complex monoalphabetic substitution cipher with multiple combinations. Yet her enemies were able to decipher the messages, and the information was enough to sentence the queen to death.

Gronsfeld cipher, or polyalphabetic substitution

Simple ciphers are considered useless by cryptography. Therefore, many of them have been modified. The Gronsfeld cipher is a modification of the Caesar cipher. This method is much more resistant to hacking and consists in the fact that each character of the encoded information is encrypted using one of different alphabets, which are repeated cyclically. We can say that this is a multidimensional application of the simplest substitution cipher. In fact, the Gronsfeld cipher is very similar to the one discussed below.

ADFGX encryption algorithm

This is the most famous World War I cipher used by the Germans. The cipher got its name because the encryption algorithm led all ciphergrams to alternate these letters. The choice of the letters themselves was determined by their convenience when transmitted over telegraph lines. Each letter in the cipher is represented by two. Let's look at a more interesting version of the ADFGX square that includes numbers and is called ADFGVX.

The algorithm for composing the ADFGX square is as follows:

1. We take random n letters to denote columns and rows.
2. We build an N x N matrix.
3. We enter into the matrix the alphabet, numbers, signs, randomly scattered across the cells.

Let's make a similar square for the Russian language. For example, let's create a square ABCD:

This matrix looks strange, since a number of cells contain two letters. This is acceptable; the meaning of the message is not lost. It can be easily restored. Let's encrypt the phrase “Compact Cipher” using this table:

Thus, the final encrypted message looks like this: “bvgvgbgdagbvdbabdgvdvaadbbga.” Of course, the Germans ran a similar line through several more ciphers. And the result was a very hack-resistant encrypted message.

Vigenère cipher

This cipher is an order of magnitude more resistant to cracking than monoalphabetic ones, although it is a simple text replacement cipher. However, thanks to its robust algorithm, it was considered impossible to hack for a long time. Its first mentions date back to the 16th century. Vigenère (a French diplomat) is mistakenly considered its inventor. To better understand what we are talking about, consider the Vigenère table (Vigenère square, tabula recta) for the Russian language.

Let's start encrypting the phrase “Kasperovich laughs.” But for encryption to succeed, you need a keyword - let it be “password”. Now let's start encryption. To do this, we write down the key so many times that the number of letters from it corresponds to the number of letters in the encrypted phrase, by repeating the key or cutting it off:

Now, using the coordinate plane, we look for a cell that is the intersection of pairs of letters, and we get: K + P = b, A + A = B, C + P = B, etc.

We get that “Kasperovich laughs” = “abvyusnyugshch eykhzhgal.”

Breaking the Vigenère cipher is so difficult because frequency analysis requires knowing the length of the keyword for it to work. Therefore, hacking involves randomly throwing in the length of a keyword and trying to crack the secret message.

It should also be mentioned that in addition to a completely random key, a completely different Vigenère table can be used. In this case, the Vigenère square consists of the Russian alphabet written line by line with an offset of one. Which brings us to the ROT1 cipher. And just like in the Caesar cipher, the offset can be anything. Moreover, the order of the letters does not have to be alphabetical. In this case, the table itself may be a key, without knowing which it will be impossible to read the message, even knowing the key.

Codes

Real codes consist of correspondences for each word of a separate code. To work with them, you need so-called code books. In fact, this is the same dictionary, only containing translations of words into codes. A typical and simplified example of codes is the ASCII table - the international cipher of simple characters.

The main advantage of codes is that they are very difficult to decipher. almost does not work when hacking them. The weakness of the codes is, in fact, the books themselves. Firstly, their preparation is a complex and expensive process. Secondly, for enemies they turn into a desired object, and intercepting even part of the book forces them to change all the codes completely.

In the 20th century, many states used codes to transmit secret data, changing the code book after a certain period. And they actively hunted for the books of their neighbors and opponents.

"Enigma"

Everyone knows that Enigma was the main Nazi encryption machine during World War II. The Enigma structure includes a combination of electrical and mechanical circuits. How the cipher turns out depends on the initial configuration of the Enigma. At the same time, Enigma automatically changes its configuration during operation, encrypting one message in several ways throughout its entire length.

In contrast to the simplest ciphers, Enigma gave trillions of possible combinations, which made breaking encrypted information almost impossible. In turn, the Nazis had a specific combination prepared for each day, which they used on a specific day to transmit messages. Therefore, even if Enigma fell into the hands of the enemy, it did not contribute in any way to deciphering messages without entering the necessary configuration every day.

They actively tried to break Enigma throughout Hitler's military campaign. In England in 1936, one of the first computing devices (Turing machine) was built for this purpose, which became the prototype of computers in the future. His task was to simulate the operation of several dozen Enigmas simultaneously and run intercepted Nazi messages through them. But even the Turing machine was only occasionally able to crack a message.

Public key encryption

The most popular of which is used everywhere in technology and computer systems. Its essence lies, as a rule, in the presence of two keys, one of which is transmitted publicly, and the second is secret (private). The public key is used to encrypt the message, and the secret key is used to decrypt it.

The role of the public key is most often a very large number, which has only two divisors, not counting one and the number itself. Together, these two divisors form the secret key.

Let's look at a simple example. Let the public key be 905. Its divisors are the numbers 1, 5, 181 and 905. Then the secret key will be, for example, the number 5*181. Would you say it's too simple? What if the public number is a number with 60 digits? It is mathematically difficult to calculate the divisors of a large number.

For a more realistic example, imagine that you are withdrawing money from an ATM. When a card is read, personal data is encrypted with a certain public key, and on the bank’s side the information is decrypted with a secret key. And this public key can be changed for each operation. But there are no ways to quickly find key dividers when intercepting it.

Font durability

The cryptographic strength of an encryption algorithm is its ability to resist hacking. This parameter is the most important for any encryption. It is obvious that the simple substitution cipher, which can be deciphered by any electronic device, is one of the most unstable.

To date, there are no uniform standards by which the strength of a cipher can be assessed. This is a labor-intensive and long process. However, there are a number of commissions that have produced standards in this area. For example, the minimum requirements for the Advanced Encryption Standard or AES encryption algorithm, developed by NIST USA.

For reference: the Vernam cipher is recognized as the most resistant cipher to crack. At the same time, its advantage is that, according to its algorithm, it is the simplest cipher.