Abstract
In recent years, cloud computing has played an important role in accessing services around the world. Thanks to its rapid development in the IT industry it has gained huge appeal. It offers users the ability to store, retrieve and share data and resources with other users however and whenever they wish. Availability, confidentiality and integrity are key issues in cloud computing. The open nature of the technology and public access make data and applications in a single cloud vulnerable to multiple security breaches such as single point of failure and malicious insiders. To overcome such issues, the data is stored in a multi-cloud environment. In this paper, we integrate different security approaches in order to provide a new lightweight security framework for authentication and data storage in multi-cloud environment using three main algorithms: certificate authentication for user identification, Blowfish for data encryption, and RSA for the transfer of Blowfish's secret key. The proposed solution is evaluated based on download time, upload time and access time. Analysis of the experimental results shows that the proposed architecture guarantees secure, fast and lightweight access to data while preserving data confidentiality against unauthorized third parties.