Cloud computing has emerged as a new promising field in the internet. It can be thought as a new architecture for the next generation of IT enterprises. It allows the user to access virtualized resources over the internet which can be dynamically scaled. Here, the owner's data is stored at a distributed data centre, which are responsible for its security constraints such as access control and data transmission to user. As the owner does not have physical access on their own data, the data centres are not trustworthy, this resulted in the cloud data security demand. Today, many cloud service providers (CSPs) are using the asymmetric and public key cryptography (PKG) for authenticating and data security purposes using the digital identity of the user. To this end, this article focuses on cloud data storage and its delivery to authorized user. For this purpose, a hierarchal identity-based cryptography method is used for data security and checking the data integrity, in order to make sure that there is no alteration or modification done by a malicious attacker or CSP for its own benefit.
