Cryptography

1
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

5
Fundamentals of Cryptography

• Confidentiality
• Authenticity
• Integrity
• Availability
• Nonrepudiation

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
CryptographyQ.Qiu04

• Offer major advantages over Traditional
• systems like
• 1.lesser storage
• 3.smaller keysize
• 4.increased speed

11
Future Work Research on Quantum Cryptography5

• 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

• 1http//all.net/BOOKS/IP/cHAP2-1.HTML
• 2http//gdp.globus.org/gt4-tutorial/multiplehtml
  /ch09s03.html
• 3http//en.kioskea.net/contents/crypto/cleprivee
  .php3
• 4  Research on elliptic curve cryptography,
  Qizhi Qiu , Qianxing Xiong,2004
• 5http//www.uhisrc.com/FTB/Cryptography/FTBCrypt
  ography.pdf
• 6Distributed Operating Systems and Algorithm
  Analysis, Andy Chow Theodore Johnson,1997
• 7Wikipedia