Security is one of the major impediments to enterprises moving their resources into the cloud. So, it's not surprising that numerous cloud security companies are springing up, attempting to address specific cloud security issues, like protecting virtual machines or encrypting data in motion.

Cisco and several other investors have given $10.5 million to HyTrust, a start-up that is tackling some of the thornier security problems posed by the growing popularity of VMware's virtualization platform.

Start-up HyTrust Monday launched its first product, an appliance for enforcing security policy related to administrative use of VMware ESX servers and the VirtualCenter management console.