Virtual machines in a network may be isolated by encrypting transmissions between the virtual machines with keys possessed only by an intended recipient. Within a network, the virtual machines may be logically organized into a number of community-of-interest (COI) groups. Each COI may use an encryption key to secure communications within the COI, such that only other virtual machines in the COI may decrypt the message. Virtual machines may be automatically provisioned with configuration information, such as the encryption keys, when the virtual machine is started. The provisioning information may be created based on a template stored on a configuration server.