DES ALGORITHM

 ABSTRACT

          This project is the implementation of DES algorithm by which a file can be encrypted and decrypted.

          The encryption and decryption can be done under provision of a key. The key must be an 8 digit integer.

          DES encrypts and decrypts data in 64-bit blocks, using a 64-bit key (although the effective key strength is only 56 bits, as explained below). It takes a 64-bit block of plaintext as input and outputs a 64-bit block of cipher text.

          Since it always operates on blocks of equal size and it uses both permutations and substitutions in the algorithm, DES is both a block cipher and a product cipher.

                   DES has 16 rounds, meaning the main algorithm is repeated 16 times to produce the cipher text. It has been found that the number of rounds is exponentially proportional to the amount of time required to find a key using a brute-force attack.

                   So as the number of rounds increases, the security of the algorithm increases exponentially.

 

HARDWARE SPECIFICATION

Processor                       : Any Processor above 500 MHz

Ram                               :  128Mb

Hard Disk                      :  10 GB.

Compact Disk                :  650 Mb.

Input device                   :  Standard Keyboard and Mouse.

Output device                :  VGA and High Resolution Monitor.

SOFTWARE SPECIFICATION

Language               :   Java1.5.

Front End Tool    :   Swing, AWT.

Operating System          :   Windows 98.