Cloud computing has been around since at least 2000 when Salesforce.com emerged as one of the first major "software as a service" (SaaS) providers, offering sales automation tools for the CRM application market. Since then cloud computing has exploded, with both major vendors and lean start-ups rolling out a growing variety of cloud-based services for enterprises. Yet many enterprises have avoided cloud computing altogether or dabbled tentatively. The main obstacle to enterprise cloud deployment, according to a new survey of more than 350 IT executives by Unisys and IDG Research, is security. What can enterprise IT professionals do to help make their cloud deployments more secure? The answer can be complex.