I am working on a project in which i have created a WCF services. A user will use a web site interact with my client and my client are using desktop based application to fetch data from cloud to his desktop. Everything is working fine but my client want me to provide security to the data stored in a cloud, they told me to perform Asynchronous Encryption decryption. I don't know which algorithm is best for the security and how to implement at both the web-user side and desktop user-side. I Googled but didn't got desired result, please help to implement security in my project.