Secure and Scalable Multi-Company Management in Enterprise Cloud Storage Broker System

Abstract

CloudRAID for Business (CfB) is a proof-of-concept enterprise cloud storage broker (ECSB) system that provides data security in the cloud. It applies a single-authority ciphertext-based policy attribute-based encryption (CP-ABE) scheme into its key management system (KMS) to solve its scalability and access control issues for multi-users and multi-devices scenarios. Unfortunately, this approach is not suitable for managing multiple companies as CfB customers since it could not provide secure and scalable zero-knowledge file sharing in the system. In this paper, we propose the practical implementation of a modified multi-authority attribute-based encryption (MA-ABE) scheme for CfB to provide a better secure and scalable KMS and zero-knowledge file sharing in a multi-company management scenario. Our work allows each company to have the authority to manage its attributes and keys for the company's employees as CfB users while CfB manages multiple companies without global decryption power to decrypt the company's encrypted data. Our evaluation shows that our proposal provides better performance with the smaller size of ciphertext and key, faster processing time, and better security compared with current CfB system.