In the excellent US Government paper The Basics of Cloud Computing the authors offer this wise advice on cloud security:
"The first thing you must look into is the security measures that your cloud provider already has in place. These vary from provider to provider and among the various types of clouds. What encryption methods do the providers have in place? What methods of protection do they have in place for the actual hardware that your data will be stored on? Will they have backups of my data? Do they have firewalls set up? If you have a community cloud, what barriers are in place to keep your information separate from other companies?"
"There are many questions that you can ask, but it is important to choose a cloud provider that considers the security of your data as a major concern."
Ken Thompson (aka The BumbleBee) blogs about bioteams, virtual collaboration and business simulation at www.bioteams.com.