Efficient hierarchical cloud storage data access structure with KDC

Among various cloud services, storage is one of the fast utilizing and hugest category of cloud service. Very huge amount of data is stored at cloud storage servers by various users or organizations. With such services, various key issues are arises such as data security, confidentiality. To overcome these, the key concept was introduced such as Cryptography. In cryptography, various keys are used to encrypt or decrypt the data before uploading or downloading from cloud server. To generate the private and public key pair, distributed key generation (DKG) protocol was introduced. But within organization there is another issue is arises, regarding to authority based data access control policy. That is only user with particular authority can access data stored at cloud, based on their authority level. For this hierarchical threshold access structure (HTAS) is used along with DKG, known as HTDKG. In this, various users are divided into levels based on their designation and some threshold is assigned. At the time of data access, only specific levels users can access the specific amount of data. Because of this, all data is not revealed to any unconcern user. In existing system, HTDKG key generation and management is perform at user side which increases the management overhead. To overcome this issue, we introduced the third party Key Distribution Center (KDC), which execute the HTDKG protocol and take responsibility of all key generation, distribution and management activities. Experimental results prove that the proposed system decrease the processing time and enhances the memory utilization by utilizing of KDC.