Security is the main concern in today’s world and securing data from unauthorized access is very important. Different techniques should be used to protect confidential image data from unauthorized access as each type of data has its own features. In the natural images the values of the neighboring pixels are strongly correlated. Correlation means that the value of any given pixel can be reasonably predicted from the values of its neighbors. The proposed technique “secure image data by double encryption” provides image data security using cryptographic technique. The proposed method breaks the correlation among neighboring pixel by dividing original image into blocks of size of n pixels*n pixels (n is provided by user) and then encrypt each pixel by their position (x, y) and then encrypt each block by AES Encryption algorithm by using public key of the receiver. The result shows that the correlation between image pixels is decreased and higher entropy is achieved by using this technique.

Cryptography public key encryption Image Correlation Image encryption Image entropy