I want to know how I can implement my security algorithm on cloud storage system to test it. The main objective of my study is to design a security model for cloud data by merging between cryptography and steganography algorithms for maintaining the privacy confidentiality and integrity of cloud user data. In this model there is a three step of security:
Frist step: in this step we hash cloud data using SHA256 to obtain a condensed version of data, called a message digest to assure data integrity. The hash code is a function of all the bits of the message and provides an error-detection capability. A change to any bits in the message results in a change to the hash code.
Next: The concatenation of (message + hash code + the encryption–decryption key for the next session) is encrypted using AES256. The hash code provides the structure or redundancy required to achieve authentication. Because encryption is applied to the entire message plus hash code, confidentiality is also provided. In this model we change the encryption–decryption key every session to provide the key confidentiality.
Finally, the output of encryption phase is embedded in a cover image using steganography algorithm LSB to conceal the existence of the message. If the data is very large to be hiding in a stego image we can apply this algorithm by another method. Instead of hiding the data in a stego-image, we can hide only the hash code and the key in an image called (a stego-key) and send to user two files, the first file include the encrypted message after hashing and the second contain the stego-key. This approach can be extended to copyright protection for digital media: audio, video and images.
