Cryptography

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Basics of cryptography, starting from ancient techniques to a few modern day processes.

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  • Book: Internet Security, Cryptographic principles, algorithms and protocols by Man Young Rhee
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  • Very informative preso!
    Hi, I really interested in this topics and still new in this subject. Any recommended sites or books I should go thru for newbie?

    Thanks!
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Cryptography

  1. 1. CRYPTOGRAPHY<br />Presented By:<br />Niharjyoti Sarangi (06/232)<br />Sukant Kumar Bishi (06/231)<br />
  2. 2. Cryptography :<br />The word “Cryptography” is derived from Greek words κρυπτόςkryptós meaning “hidden” and γράφωgráfo meaning “to write”. <br />Cryptography is the practice and study of hiding information.<br />It is considered as a branch of both Mathematics and Computer Science.<br />
  3. 3. A Brief History of Cryptography :<br />Probable origin of cryptography : 2000 B.C. In Egypt. (Hieroglyphics).<br />
  4. 4. A Brief History of Cryptography (contd.) :<br />The ancient Chinese art of Cryptography: Ideography.<br />Petroglyph (An Ideograph on rock surface)<br />
  5. 5. A Brief History of Cryptography (contd.) :<br />The ancient art of Cryptography in Mesopotamia, Babylon, Assyria: Cuneiforms and Atbash ciphers.<br />
  6. 6. A Brief History of Cryptography (contd.) :<br />Spartan art of Cryptography : A system which consisted of a thin sheet of papyrus wrapped around a staff. <br /><ul><li>Messages were written down the length of the staff, and the papyrus was unwrapped. In order to read the message, the papyrus had to be wrapped around a staff of equal diameter. </li></li></ul><li>A Brief History of Cryptography (contd.) :<br />Scytale<br />
  7. 7. A Brief History of Cryptography (contd.) :<br />
  8. 8. A Brief History of Cryptography (contd.) :<br />Polybius Squares: <br />
  9. 9. A Brief History of Cryptography (contd.) :<br />Caesar Cipher: <br />Monoalphabetic Substitution<br />
  10. 10. A Brief History of Cryptography (contd.) :<br />Polyalphabetic Substitution:<br /><ul><li>Devised by Leon Battista Alberti (Father of Western cryptology)
  11. 11. Uses two concentric discs with letters written on both of them.</li></li></ul><li>A Brief History of Cryptography (contd.) :<br />Vigenere Cipher:<br /><ul><li>Uses the basics of Trithemius table but the key system is slightly changed.
  12. 12. Wrote this in his book “Tracte des Chiffres”.</li></li></ul><li>A Brief History of Cryptography (contd.) :<br />Wars:<br />
  13. 13. Elements of Cryptography:<br />Encryption<br />Decryption<br />Key<br />
  14. 14. Encryption and Decryption<br />The process of disguising a message in such a way as to hide its substance is encryption.<br />An encrypted message is cipher text.<br />The process of turning cipher text back into plaintext is decryption.<br />Plain Text<br />Cipher Text<br />Plain Text<br />Encryption<br />Decryption<br />
  15. 15. Key:<br />A key is a value that works with a cryptographic algorithm to produce a specific cipher text.<br />
  16. 16. Types of Cryptography:<br />Based on the type of key used, Cryptography is broadly categorized into:<br />Symmetric Key Cryptography<br />Asymmetric Key Cryptography<br />
  17. 17. Symmetric key Cryptography:<br />
  18. 18. DES(Data Encryption Standard):<br />
  19. 19. Asymmetric key Cryptography:<br /><ul><li>Also called as Public Key Cryptography.</li></li></ul><li>RSA Algorithm:<br />Rivest, Shamir and Adleman<br />
  20. 20. RSA Algorithm (Contd.):<br />
  21. 21. RSA Algorithm (contd.):<br />Key Generation<br />
  22. 22. RSA Algorithm (contd.):<br />Encryption<br />Decryption<br />
  23. 23. Diffie-Hellman Key Exchange:<br />
  24. 24. Applications of Cryptography:<br />ISDN<br />Kerberos<br />Kryptoknight<br />Sesame<br />PEM<br />PGP<br />Smart Cards<br />UEPS<br />Clipper Chip (MYK-78T)<br />Cap Stone (MYK-80)<br />
  25. 25. Thank You<br />Niharjyoti Sarangi<br />Sukant Kumar Bishi<br />

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