CRYPTOGRAPHY AND RC4 ENCRYPTION ANALYSIS

ABSTRACT
   
Cryptography the art of writing secret code plays a very important role in network security . There are various  existing algorithms  for encrypting and decrypting , among which the most recently and widely used algorithm is RC4 ( Rivest Cipher 4 ) . The RC4 algorithm is used identically for encryption and decryption as the data stream is simply   XORed with the generated key sequence. The algorithm is serial as it requires successive exchanges of state entries based on the key sequence. This encryption algorithm
is used by standards such as IEEE 802.11 within WEP ( Wireless Encryption Protocol ) using a 40 and 128-bit keys.There are  several weakness in the KEY SCHEDULING ALGORITHM of RC4 . There are  large number of weak keys , in  which knowledge of a small number of key bits suffices to determine many state and output bits with non-negligible probability. These keys are used to construct new distiguisher for RC4 , and to mount related key attacks with practical complexities.




Click here to download the full paper