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

1. CRYPTOGRAPHY Presented By: Niharjyoti Sarangi (06/232) Sukant Kumar Bishi (06/231)

2. Cryptography : The word “Cryptography” is derived from Greek words κρυπτόςkryptós meaning “hidden” and γράφωgráfo meaning “to write”. Cryptography is the practice and study of hiding information. It is considered as a branch of both Mathematics and Computer Science.

3. A Brief History of Cryptography : Probable origin of cryptography : 2000 B.C. In Egypt. (Hieroglyphics).

4. A Brief History of Cryptography (contd.) : The ancient Chinese art of Cryptography: Ideography. Petroglyph (An Ideograph on rock surface)

5. A Brief History of Cryptography (contd.) : The ancient art of Cryptography in Mesopotamia, Babylon, Assyria: Cuneiforms and Atbash ciphers.

7. A Brief History of Cryptography (contd.) :

8. A Brief History of Cryptography (contd.) : Polybius Squares:

9. A Brief History of Cryptography (contd.) : Caesar Cipher: Monoalphabetic Substitution

13. Elements of Cryptography: Encryption Decryption Key

14. Encryption and Decryption The process of disguising a message in such a way as to hide its substance is encryption. An encrypted message is cipher text. The process of turning cipher text back into plaintext is decryption. Plain Text Cipher Text Plain Text Encryption Decryption

15. Key: A key is a value that works with a cryptographic algorithm to produce a specific cipher text.

16. Types of Cryptography: Based on the type of key used, Cryptography is broadly categorized into: Symmetric Key Cryptography Asymmetric Key Cryptography

17. Symmetric key Cryptography:

18. DES(Data Encryption Standard):

20. RSA Algorithm (Contd.):

21. RSA Algorithm (contd.): Key Generation

22. RSA Algorithm (contd.): Encryption Decryption

23. Diffie-Hellman Key Exchange:

24. Applications of Cryptography: ISDN Kerberos Kryptoknight Sesame PEM PGP Smart Cards UEPS Clipper Chip (MYK-78T) Cap Stone (MYK-80)

25. Thank You Niharjyoti Sarangi Sukant Kumar Bishi