Efficient ABBE for Improving Cloud Security in a Dynamically Changing User Environment

Abstract

The existing scenario to store a large amount of data in a centralized server is complex as the information stored is immense. To avert this organizations move to cloud this causes some security issues. The paper focuses on ABBE (Attribute Based Broadcast Encryption) which is an enhancement of ABE (Attribute Based Encryption) which uses ABE to encrypt the data (AES key) and then broadcasts the cipher in order to provide fine grained access. This also avoids collusion and excess key generation. In addition to this multiple data owner scenario scheme is part of our proposal wherein the whole system is divided into multiple domains. AES encryption is used to encrypt data and ABBE to encrypt the AES key to be broadcasted. ABBE has minimized implementation complexity and less effort with respect to computation when compared to that of ABE. This imposes no limit on the attribute’s size, when those attributes sets are used for encryption and has a huge attribute universe. Also the cost of cryptographic functions like encryption and decryption is minimum. It also enables modification of accessibility or modification of attributes dynamically and also it supports effective user or attribute revocation as per the demand. By having multiple domains the management complexity of keys is also minimum. This novel framework is developed for educational institutions to securely share the information through cloud.