Tutorial on

Introduction to Cryptography and Network Security

A tutorial on "Introduction to Cryptography and Network Security" will be held on 21st November 2015 from 10:30 A.M. to 12:30 P.M.


Cryptography is a subject which primarily deals with how one can modify a readable text or document/object to unreadable text or document/ object. In cryptography there are two different approaches one is called encryption algorithm by which one can modify the readable text to some encrypted form which the people cannot read or understand. The second approach is just the reverse of encryption that means to get back the original text or object from encrypted form by using some algorithm called decryption algorithm. Generally the decryption algorithm is the reverse process of encryption algorithm. The encryption or the decryption methods are of two types such as (i) Symmetric Key Cryptography where one key is used for encryption as well as decryption purpose and (ii) Public key cryptography where we use one key called public key for encryption purpose and another key called private key which is used for decryption purpose. The encryption key is distributed to all senders and the decryption key is distributed to the receiver only. In this tutorial the authors will try to focus on different symmetric key algorithms including some recent trends in symmetric key encryption methods and also discuss the public key cryptography including RSA algorithm.


The objective of the presentation is to explore and to implement some efficient cryptography methods. The authors will discuss some simple and then efficient symmetric key and asymmetric key cryptography methods namely (i) Caeser cipher method, (ii) Modified caeser cipher method, (iii)Hill cipher method, (iv) Diffie -Hellman key exchange method, (v) Playfair method, (vi)Meheboob, Saima and Asoke(MSA) algorithm and some recent methods of symmetric key algorithm and also some public key algorithms such as (i) Rivest Shamir and Adleman(RSA) method. The presentation will help not only the beginners but also the experts in this field.

Intended Audience:

The target audience may be of 2 categories:
(i) The first category of audience may be expert in different discipline and now they want to learn what is network security and cryptography.
(ii) The second category of audience those who are working in cryptography and wants to know more about it.

This presentation will help both beginners as well as the experts in the area of network security and cryptography. The lecture material will definitely help the students and researchers to start work on cryptography.

Outline of Tutorial:

  • Introduction of Cryptography
  • Some Classical Cryptography Algorithms
  • Modified Caesar Cipher Method
  • Transposition Method
  • Vernam Cipher Method
  • Hill Cipher Method
  • Playfair Method
  • Diffie-Hellman key exchange Method
  • Data Encryption Standard(DES) Method a brief overview
  • Advanced Encryption Standard(AES) Method a brief overview
  • Introduction to Public key cryptography: Rivest Shamir Adleman (RSA) method
  • Some recent Symmetric key algorithms developed by Nath et. al.
  • Symmetric Key Cryptography using Random Key Generator: Meheboob, Saima and Asoke(MSA) method
  • A new Symmetric key Cryptography Algorithm using extended MSA method: DJSA symmetric key algorithm
  • New Symmetric key Cryptographic algorithm using combined bit manipulation and MSA encryption algorithm: NJJSAA symmetric key algorithm
  • Symmetric key cryptosystem using combined cryptographic algorithm- generalized modified vernam cipher method, MSA method and NJJSAA method: TTJSA algorithm
  • Ultra Encryption Standard (UES) Version-I: Symmetric Key Cryptosystem using generalized modified Vernam Cipher method, Permutation method and Columnar Transposition method
  • Modern Encryption Standard Version-I: Bit level exchange and random byte reshuffling algorithm: MES-I
  • Bit Level Encryption Standard(BLES) Version I & II
  • Multi Way Feed Back Encryption Standard version-1(MWFES-1)
  • 3-dimensional Multi Way Feedback Encryption Standard (3dMWFES)
  • Digital Signatures
  • Introduction
  • Message Digests
  • Message Digest Algorithm
  • Introduction to Kerberos
  • Conclusion
  • References

Tutorial Organizers

Dr. Ashoke Nath
Associate Professor
Department of Computer Science
St. Xavier's College (Autonomous)
Kolkata, India
e-mail: asokejoy1@gmail.com

Ms. Joyshree Nath
Academic Counselor
Indira Gandhi National Open University
St. Xavier's College (Autonomous)
Kolkata, India
e-mail: joyshreenath@gmail.com