Data coloring and software watermarking techniques protect shared data objects and ensures the security level in the cloud. These techniques safeguard multi-way authentications, enable single sign-on in the cloud, and strengthen the security for accessing confidential data in both public and private clouds.

There are the following attach file will help you

Also the links:

http://link.springer.com/article/10.1007%2Fs11633-011-0583-3#page-1

http://www.scopemed.org/?mno=28805

What is data coloring?

In a program, the consistency constraints with shared data structures.are called Colors.   Generally a programmer will be assigning colors to data. As a part of coloring,  the programmer also marks places in the control flow where data should be made consistent.

How we can utilize digital watermarking algorithms to provide security for images that we are keeping in a cloud storage, that is actually managed by third party?

Water mark is computed for a given digital object and placed along with the same object. Water mark is basically digitally signed emblem. This can be verified by any third party similar to that of process used for verifying the digitally signed certificates.

This paper help

A Method for Trust Management in Cloud Computing: Data Coloring by Cloud Watermarking

International Journal of Automation and Computing