Improving the Security of the Shi Reversible Data Hiding Algorithm

In this paper, we propose a method for cryptanalysis of the Shi reversible data hiding algorithm. We also propose a method to improve its security by using the concepts in number theory. Our security improvement part encrypts the data by four keys before embedding it in the digital image and in the detection part the keys are used as side information to recover the original data. Theoretical analysis and experimental results shows that finding the original data from the marked image after applying our proposed algorithm is not feasible in a reasonable time.