Cloud Computing is a paradigm which supports data storage and access at pay per use mode. The outsourced data may be sensitive and may cause undesired consequences when it is accessed by unauthorized persons. To protect such precious personal data, practically, data owner employs encryption techniques. Revealing data search pattern and access pattern also leads to problem. No information like sensitivity of data, location of data, size of data, etc., shall be revealed to anonymous. Many techniques exist to protect such information where this paper concentrates on few techniques which are employing for content confidentiality, search pattern confidentiality and access confidentiality. Several articles which deal with these concepts are discussed and best methods are explored.