Physical access controls are another important layer of preventive controls. Controlling physical access to the system is absolutely essential. Within a few minutes, a skilled attacker with unsupervised direct physical access to the system can successfully obtain access to sensitive data by inserting special boot disks that provide a person with unfettered privileges and rights on that computer. Someone with unsupervised physical access to a workstation could also install a keystroke logger device that would capture the victim’s passwords. When the attacker returns later and retrieves the device, the captured credentials can then be used to successfully impersonate the victim and gain unauthorized access to system resources