1. CSc 8320 Advanced Operating Systems Barnali Chakrabarty
Cryptography
CSc 8320
Advanced Operating Systems
Barnali Chakrabarty

2. Overview What is Cryptography ? Its history And its fundamentals
Public and Private Cryptographic Systems
Current Work
Future Research

3. What is Cryptography ?
The process of converting intelligible information called the plain text into something that is unintelligible, called the cipher text

4. History of Cryptography
2000 BC in Egypt
Atbash Cipher
Caesar Cipher
around 2000 B.C. in Egypt, where hieroglyphics were used to decorate the tombs of deceased rulers and kings. These hieroglyphics told the story of the life of the king and proclaimed the great acts of his life. They were purposefully cryptic, but not apparently intended to hide the text. Rather, they seem to have been intended to make the text seem more regal and important.

5. Fundamentals of Cryptography
Confidentiality Authenticity Integrity Availability Nonrepudiation
Confidentiality is the term used to prevent the disclosure of information to unauthorized individuals or systems.
Authenticity implies that the data, transactions, documents should be genuine.Integrity- data cannot be modified
Without authorization.

6. Public Key Cryptographic Systems
asymmetric key algorithms
the key used to encrypt a message is not the same as the key used to decrypt it

7. Diffie Hellman Algorithm: A public key Cryptographic Algorithm

8. Private Key Cryptographic Systems
- Also called Symmetric encryption involves using the same key for encryption and decryption.

9. One Time Pad: A Private Key Cryptographic Algorithms
The plain text is combined with a secret random key only once to produce the cipher text

10. Current Work :Research on Elliptic Curve Cryptography[Q.Qiu04]
Offer major advantages over Traditional systems like 1.lesser storage 3.smaller keysize 4.increased speed

11. Future Work: Research on Quantum Cryptography[5]
based on photon physics. A photon vibrates as it travels through space. The angle
of vibration is known as polarization of the photon. Using different polarizations, the sender can transmit a unique symmetric key to receiver each time she needs to send a message. Theoretically,the eavesdropper has no chance to intercept this key because of unique properties of quantum physics

12. References [1]http://all.net/BOOKS/IP/cHAP2-1.HTML
[2]
[3]
[4]  Research on elliptic curve cryptography, Qizhi Qiu , Qianxing Xiong,2004
[5] y.pdf
[6]Distributed Operating Systems and Algorithm Analysis, Andy Chow & Theodore Johnson,1997
[7]Wikipedia