• Ms. Akshada Devidas Yevatkar
• Dr.S.Y. Amdani
• Dr.S.A. Bhura

The Cloud based applications for the purpose of providing security to the outsourced documents receives more attention of internet users nowadays. The cloud enables on demand scalable and cost-effective services for documents storage. To achieving unbreakable data security to the outsourced documents we have “Encryption”. With the popularity of using Encryption-Decryption, for storing data in the cloud, it has number of challenges to utilize it efficiently with all users in the workspace and make it worth with the cloud. Since the Encryption limits the admission of new users in the existing access policy, for that reason Attribute Based Encryption receives widespread attention of the researchers. In ABE, if the user holds required attributes, then only the user will be able to acquire the plaintext, otherwise will not be able to perform the decryption.This is the first scenario of achieving the unbreakable security for outsourced documents in the cloud. On the other side of cloud environment, to increase productivity of the cloud, collaboration with more users is necessary. But the ABE limits the admission of newly authorized user is challenging issue to solve, because the access policies are fixed at the time of ciphertext creation, and when the ciphertext is need to be share with others legally there will be necessity of extending an original access policy specified in ABE. In this process, at the time of extending policy, data uploader had to download ciphertext, modify the access policy as per latest requirements and then reupload the data with modified access permissions. This significantly increases the processing time to extend access policy and consumes server space unnecessarily. In this paper to address above problem we propose modified attribute-based encryption with time varying encryption scheme for document encryption which is based on the research of Time Varying Camellia Encryption Algorithm for the cloud storage environment and a novel solution for access permission management in which we will use XML file to store access permission. Finally, we discuss the evaluation result observed with existing work concept and proposed system.

Time varying encryption, Extended Access Control, Collaboration in cloud, Attribute Based Encryption.

"Performance Enhancement for an Attribute Based Encryption and Access Control Scheme for Cloud Storage Environment", International Journal of Emerging Technologies and Innovative Research (www.jetir.org), ISSN:2349-5162, Vol.5, Issue 8, page no.234-240, August-2018, Available :http://www.jetir.org/papers/JETIR1808676.pdf

"Performance Enhancement for an Attribute Based Encryption and Access Control Scheme for Cloud Storage Environment", International Journal of Emerging Technologies and Innovative Research (www.jetir.org | UGC and issn Approved), ISSN:2349-5162, Vol.5, Issue 8, page no. pp234-240, August-2018, Available at : http://www.jetir.org/papers/JETIR1808676.pdf