Theme: Stenographic protection of information. Cryptographic protection of information Plan: The concept of cryptography
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- Encoding
- The key
- Asymmetric encryption algorithms.
- The RSA Algorithm The RSA Algorithm
- Steganography Stenography
Theme:Stenographic protection of information. Cryptographic protection of information Plan: 1. The concept of cryptography 2. Symmetric encryption algorithms 3. Asymmetric encryption algorithms. A cipher or cryptosystem is used to encrypt information. The actual unencrypted data is called plaintext, and the result of encryption is called ciphertext. Decryption will be necessary to recover the actual data. The key is used to configure the cryptosystem for encryption and decryption. The appearance of the cryptosystem as a "black box" is presented in the figure. Encoding and cryptography methods are used to protect information. Encoding refers to the process of transferring information from one system to another in a specified order using certain symbols. Cryptography refers to the method of encrypting the content of a secret message, that is, the method of preventing unauthorized access to information by changing the data according to a special algorithm and creating an encrypted text. The key is the information needed to encrypt and decrypt the text. Cryptanalysis - studies the possibilities of deciphering the encrypted text without knowing the key. In cryptographic protection, the following requirements are imposed on passwords: • sufficient cryptoresistance; • simplicity of the encryption and return process; • no increase in their size as a result of information encryption; • invulnerability to small encryption errors Information related to encryption and decryption, compiled in a certain alphabet, constitutes texts. An alphabet is a finite number of symbols used to represent information. As examples: • Uzbek language alphabet consisting of twenty-six characters (letters); • Russian alphabet consisting of thirty-two characters (letters); • Latin alphabet consisting of twenty-eight characters (letters); • ASCII computer character alphabet consisting of two hundred and fifty-six characters; • binary alphabet, that is, an alphabet consisting of 0 and 1 characters; • alphabets consisting of octal and hexadecimal numbers can be cited. Symmetric ciphers use the same key to encrypt and decrypt data. Symmetric encryption algorithms: • Replacement algorithm • Viginer algorithm • Vernam algorithm • Caesar algorithm • DES (Data Encryption Standard) • AES (Advanced Encryption Standard) • GOST 28147-89RC5 • (Ron's Code 5 or Rivest's Cipher 5) • Blowfish • Twofish Vijenera algorithm Vijenera algorithm There are also public-key (asymmetric) cryptosystems, in which two keys are used for encryption and decryption. Asymmetric encryption algorithms. • RSA method (abbreviation for Rivest, Shamir and Adelman) • The El-Gamal Method • DSA (Digital Signature Algorithm) • ECDSA (Elliptic Curve Digital Signature Algorithm) The RSA Algorithm The RSA Algorithm Steganography Stenography is the concealment of communication by hiding a secret message in a fake message. In other words, the main idea of steganography is to prevent suspicion about the existence of secret information. Download 1.08 Mb. Do'stlaringiz bilan baham: |
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