A boot block that contains a first public key is activated and a system Basic Input/Output System (BIOS) that contains a second public key and a first digital signature is verified, the verifying being performed by confirming that the first and second public keys match. In response to a determination that the first and second public keys match, the BIOS is activated and a system image is loaded to a real device. The system image is verified by confirming that the first digital signature that is stored in the system BIOS matches a second digital signature that is stored in a mass storage device. In response to the first and second digital signatures matching, a virtual mass storage device is created. Control of the virtual mass storage device is transferred to a boot strap code in an operating system image and the operating system image is booted from the virtual mass storage device.