An Approach to Selective Encryption on Compressed Image

Advancement in technology has made the traffic of digital image mainly in the field of medical application a daily routine. Now a day's transmission of medical image especially over wireless is very common. But with the concern for security of image is also growing proportionally resulting from the increasing amount of imaging data. Two important measures for evaluating an encryption system are speed of encryption and security levels. Low computational cost and low storage requirement is the demand of mass. A lot of researches [1-12] have been made to give the image the maximum security level by means of an encryption system which runs in resource constrained device. Selective Encryption is an approach to reduce the computational resources for large imaging data. In this technique a part of image is encrypted keeping the remaining part unencrypted. Here we apply a static HUFFMAN coding for compressing image data and apply Selective Encryption with our proposed algorithm. The experimental study shows that above 90% damage of original file can be achieved by only encrypting 60% to 70 of original file using the proposed technique.