26-12-2012, 06:25 PM
SERPENT-CRYPTOSYSTEM
SERPENT.pptx (Size: 385.16 KB / Downloads: 35)
History :
In order to overcome the issue of secrecy of DES “NIST” called for a successor algorithm which would be called the AES(advance encryption standard) with the basic requirement
-128 bits block cipher .
-Symmetric key encryption .
-key size : 128,192,256 bits.
-Faster than 3DES.
-As secure as 3DES.
Serpent was the finalist of AES competition.
Introduction :
Serpent is a 32-round substitution permutation network(SPN)operating on four 32bit words.
Serpent encrypts a 128bit plain text P to a 128 bit cipher text C in 32 rounds with 33 keys.
In 1997 Serpent was designed by Eli Biham ,
Ross Anderson , Lars Knudsen .
Serpent was designed to work parallel processing system.
Encryption technique :
Issued should be discussed here
(i) block diagram.
(ii) initial and final permutation .
(iii) linear transformation.
(iv) Serpent S-box.
(v) Key scheduling algorithm.
Decryption technique :
To decrypt the message using serpent algorithm we have to proceed in inverse order i.e. to get the plain-text message we have to use inverse of Sboxes and inverse of linear transformation