SYNOPSIS NETWORK SECURITY USING CRYPTOGRAPHY TECHNIQUES IN NS-2 3rd YEAR, ECE BRANCH SUBMITTED BY - HARSHIT AGGARWAL (09102275) ANSHUL NARESH JAIN (09102232) SUPERVISOR - MR. JAWAID ALAM

Submitted in partial fulfillment of the Degree Of Bachelor of Technology DEPARTMENT OF ELECTRONICS & COMMUNICATION JAYPEE INSTITUTE OF INFORMATION TECHNOLOGY UNIVERSITY, NOIDA

AIM OF THE PROJECT
NS-2 is an open source and very popular network simulation system. It provides support for IP protocols suite and many standard routing protocols for wire and wireless networks.Implementation of security on NS-2 is necessary in network simulation. However, currently, NS-2 does not support these features. Our project will aim to solve this issue.The purpose of the project is to find a way to add encryption/decryption features into network simulation program NS-2.

GENERAL APPROACH TO PROJECT
In order to experiment security features for network, we need to add security functions into NS-2. Our approach is to build a new protocol at network layer – IP layer. We also define new packet format to represent new protocols. The new protocol is represented by a class derived from built-in class in NS-2. Within new derived class we will add encryption and decryption for data field in the data packet. We will also implement message digest generation function to ensure the integrity of data packet during transmission. We consider our data as plain text.

ENVIRONMENT DEVELOPMENT REQUIREMENTS 1. Personal Computer Windows 2000 professional and later. 2. NS-2 version 2.27 3. C/C++ editor.

CRPTOGRAPHY TECHNIQUE USED
Caesar cipher
In cryptography, a Caesar cipher, also known as a Caesar's cipher, the shift cipher, Caesar's code or Caesar shift, is one of the simplest and most widely known encryption techniques. It is a type of substitution cipher in which each letter in the plaintext is replaced by a letter some fixed number of positions down the alphabet. For example, with a shift of 3, A would be replaced by D, B would become E, and so on. Caesar cipher

Hash function:
Using a simple hashing algorithm to get hashed value from a string of plain text. The hash value will be attached to packet header for data integrity checking. At the other end of communication, after decryption, the decrypted text will be hashed again to get new hashed value. This new hashed value will be compared to the value attached within packet header. If they are equal, the data integrity is ensured and decrypted text is accepted; otherwise the packet is discarded. In either case, an acknowledge packet will be sent back to sender to inform of the status of the packet.

LOGICAL DESIGN Sender Receiver
HASH FUNCTION
Encrypted text + Hash
Decrypted text ACKNOWLEDMENT ACKNOWLEDMENT SYSTEM CONSOLE SYSTEM CONSOLE
Plain text
Encrpted text + Hash value
ENCRYPTION:Caesar cipher with a key
Compare hashed value DECRYPTION:Caesar cipher with key HASH FUNCTION