Using the cloud, businesses may share and access computer resources on-demand from anywhere in the world, creating new opportunities for data processing and services while simultaneously lowering computing and storage costs for end users. One of the most important cloud security solutions is access control, which is used by both businesses and people to secure sensitive data. The cloud's centralised access control method makes it easier for hackers or cloud internal management to tamper with or leak critical data. As a solution to this problem, the Auto Privacy Chain, a block chain-based access control framework with privacy protection, is reviewed with generic models: Block chain based architecture for demand and supply, Block chain based Internet of medical things for healthcare services, and Bitcoin Pay architecture. Auto Privacy Chain's access control, permission, and revocation design procedures offer customers with security

Keywords : Cloud, Blockchain , Access control frame work.