Security over Cloud Data through Encryption Standards

In cloud computing, data owners upload their data to the public cloud server. The server may not be secured so it can be attacked easily and data can be taken from the server. For many security reasons this data has to be encrypted before uploading it to the cloud server. In the proposed system data owners encrypt their data before uploading by creating a key for security, and the users search their required data in the cloud server. If the data is found, it is received by the user in the encrypted form. To decrypt the data the user has to be authenticated by the data owner. After verifying the user, the data owner provides the security key to the user along with the Message Authentication Code (MAC). The message authentication code is generated by the data owner at the time of uploading itself. The user can decrypt the data using the key provided by the data owner and check the integrity of data using Message Authentication Code (MAC). Data integrity is also very important to check whether any data is missing or not. Security for data is provided by using various cryptographic methods. We establish a strict encryption algorithm i.e. Blowfish algorithm so that our system will have greater security. We encrypt the data index for efficient matching of data in the server so that the server will provide accurate search results to the user. Our proposed system also avoids Data piracy in the cloud server.