In fine-grained access control, each data item has its own access control policy. The entity that wants to access a data item needs to provide its credentials to the policy enforcer to allow the enforcer to check the eligibility of the entity. This paper describes a middleware that relieves the programmers from carrying out the complicated fine-grained access control tasks when they develop applications that run in a cloud environment. In a cloud environment, a policy enforcer is normally not the owner of the data. To preserve the privacy and the security of the data owners and the entities that access the data, the middleware uses a scheme that allows the policy enforcer to carry out access control without understanding the meaning of the access control policies of data and the credentials of entities. Compared with existing schemes, the proposed middleware provides better privacy, and, it is more efficient than existing schemes.