Multiple Blocks, Multiple Rounds Method for Image Cryptography

In this research paper a simple, flexible, secure and efficient method of digital image cryptography will be introduced. The method will enhance some features of standard methods like DES and AES. The introduced method will divide the source data into blocks, the block size will be variable, the number of rounds will be also variable and they will be determined by the user when selecting the private key. The proposed method will use a complicated private key, which will provide a huge key space capable to resist hacking attacks, the produced decrypted data will be very sensitive to the selected private key, any minor changes in the key will be considered as a hacking attempt by producing damaged decrypted data. The private key will be used to divide the image into blocks, to set the number of rounds and to generate the required for rounds secret keys. The private key will contain the values of chaotic parameters to run two chaotic logistic map models to generate two 2D chaotic keys; these keys will be converted to decimal integers to apply the required XORing operations. The proposed method will be tested and implemented using various images; the obtained results will be used to prove the enhancement provided by this method: quality of cryptography, security, speed and sensitivity.