In today's world, we deal with various online services, where each person deals with various technologies. These technologies are made for people to make our access to the new world easily. There is a tremendous use of online applications, websites which require large storage. Large data is handled by the online systems. The collection of data in the whole world is about 20% in the last few years. The data is captured from the user, controlled by the systems, and operations are performed on data. It requires more system accuracy and protection to personal data. But the person does not know about the data, where and how it is used where it is stored or whether the data is handled by some organisations for their own use or data is been hacked by another person. This chapter explores protection of data using the decentralized privacy of blockchain.