Data integrity verification is one of the biggest security issue when storage of the data in necessary over cloud. Different methods are available for checking the integrity of data where Provable data possession is one of them. In this paper, the authors have concentrated on the creation of an efficient PDP method for distributed cloud storage, in which they consider the existence of multiple cloud service providers maintaining and storing client's data in cooperative manner. This cooperatively working PDP method is based on indexing hierarchy method. They show the security of their scheme based on trusted third party and zero-awareness proof structure, which can fulfill reliability of awareness, completeness, and properties.