Design and Evaluation of Performance of Cryptography Technique based on DES

Cryptography is an emerging technology which uses the characteristics of human vision to decrypt encrypted images. It does not require cryptography knowledge and complex computation. It also ensures that hackers cannot perceive any clues about a secret image from individual cover images for security concerns. There are many challenges, which one face when design a security model. The requirements of the security model depend upon the type of data to be encrypted. There is main problem to be considered, is the computational speed of the encryption model. There are many security models, which provide high level of security. Such model increases the execution time for encryption. The effectiveness of the algorithms highly depends upon computational time or computational speed. There is a main problem to Mono-alphabetic Cipher, that it can be broken because same plain letters are encoded to same cipher letter and the underlying letter frequencies remain unchanged. This problem can be solved by assigning various cipher letters or symbols to same plain letters. This can be implemented by a poly-alphabetic ciphering and deciphering technique. The proposed method is based on DES and it has similar properties and structure to DES with much smaller parameters. The proposed encryption algorithm takes an 8-bit block of plaintext (example: 10111101) and a 10-bit key as input and produces an 8-bit block of cipher text as output. The proposed decryption algorithm takes an 8-bit block of cipher text and the same 10-bit key used to produce that cipher text as input and produces the original 8-bit block of plaintext. A time effective symmetric key algorithm for small amount of data has been proposed. The performance of proposed technique will be evaluated through text received and computation time. MATLAB R2013a will be used as an implementation platform.