Existing Commercial Cloud Services In normal network-based applications, user authentication, data confidentiality, and data integrity can be solved through IPSec proxy using encryption and digital signature. The key exchanging issues can be solved by SSL proxy. These methods have been applied to today‘s cloud computing to secure the data on the cloud and also secure the communication of data to and from the cloud. The service providers claim that their services are secure. This section describes three secure methods used in three commercial cloud services and discusses their vulnerabilities.
