Biblio
Now a day's cloud computing is power station to run multiple businesses. It is cumulating more and more users every day. Database-as-a-service is service model provided by cloud computing to store, manage and process data on a cloud platform. Database-as-a-service has key characteristics such as availability, scalability, elasticity. A customer does not have to worry about database installation and management. As a replacement, the cloud database service provider takes responsibility for installing and maintaining the database. The real problem occurs when it comes to storing confidential or private information in the cloud database, we cannot rely on the cloud data vendor. A curious cloud database vendor may capture and leak the secret information. For that purpose, Protected Database-as-a-service is a novel solution to this problem that provides provable and pragmatic privacy in the face of a compromised cloud database service provider. Protected Database-as-a-service defines various encryption schemes to choose encryption algorithm and encryption key to encrypt and decrypt data. It also provides "Master key" to users, so that a metadata storage table can be decrypted only by using the master key of the users. As a result, a cloud service vendor never gets access to decrypted data, and even if all servers are jeopardized, in such inauspicious circumstances a cloud service vendor will not be able to decrypt the data. Proposed Protected Database-as-a-service system allows multiple geographically distributed clients to execute concurrent and independent operation on encrypted data and also conserve data confidentiality and consistency at cloud level, to eradicate any intermediate server between the client and the cloud database.