virtualbox.org

Is it possible to secure a VirtualBox machine (vdi resides on external HDD) by marrying it exclusively to one host? I want to make sure that, in case my external HDD is lost, the VirtualBox machine created on it cannot be set up to run again anywhere else. I am thinking maybe marrying the host's UUID to the VM or the host's MAC address, or something unique that only this host machine has.

Not much point really. Anyone with any knowledge of VirtualBox would simply create a new VM using the existing vitual hard disk. A better plan would be to encript the the virtual disk.