Already Google has made their reputation in the field of cloud storage service. Now it offers free security service to its cloud storage users. It is adding a free encryption to cloud storage. Google Cloud Storage product manager Dave Barth stated “There is no setup or configuration required, no need to modify the way you access the service and no visible performance impact. The data is automatically and transparently decrypted when read by an authorized user. If you require encryption for your data, this functionality frees you from the hassle and risk of managing your own encryption and decryption keys.”
Even if you have stored the files previously then also the files can be gradually encrypted and re-written to disk in coming days. Before writing to cloud storage you can encrypt your data. Google says “Commitment to evolve the security capabilities of our platform".