Before migrating to the Amazon Web Services (AWS) Cloud, customers may have been responsible for the entire control set in their security compliance and auditing program. With a shared responsibility model, AWS shares the security responsibilities with you: AWS is responsible for the security “of” the cloud, while the customer is responsible for security “on” the cloud. Customers’ cloud surfaces are dynamic, elastic, and on-demand. This means exposures can also be dynamic within the customers’ part of the shared security model.