Abstract

Abstract- Security and privacy are very important issues in cloud computing. In existing system access control in clouds are centralized in nature. The scheme uses a symmetric key approach and does not support authentication. Symmetric key algorithm uses same key for both encryption and decryption. A single Key Distribution Centre (KDC) distributes secret keys and attributes to all users. A new decentralized access control scheme for secure data storage in clouds that supportsanonymous authentication is developed. The validity of the user who stores the data is also verified. The proposed scheme is resilient to replay attacks. In thisscheme. Data Owner can share the data and it-s Key to the Permitted users. Data Sharing is achieved for three types of users. 1. User Based 2. Role Based (Position / Role), 3. Attribute (Experience). Data is uploaded by the Data Owner based on public key, secret key, Global key and Group key. Public key is randomly generated. Secret key & group key is generated via Attribute. Global key is generated randomly.We encrypt the uploaded file using ABE Algorithm.

Authors and Affiliations