[DataVault X4 Multi-Network Secure Computer]

An electromechanical high-level security lock/key which is connected to the ON/OFF function of the main computer case power supply will activate and power-on both computer domains when the authorized user inserts the high-level security key. The key of said electromechanical high-level security lock must be inserted and turn clockwise to the ON position by the authorized user first. The unsecured domain will be accessible first by default without any other access control requirement. It is impossible to turn-on the multileveled custom secured computer without the key. The key cannot be removed in the ON position. It can only be removed in the OFF position, when both, the secured and unsecured domains are no longer in use and the user has shut down their respective operating systems (OS).

A custom-built Y power cable from the computer case power supply provides power to both domains or central processing units or motherboards, the unsecured domain and the secured domain.

An aluminum-based electromagnetic field (EMF) shield is placed between the two central processing units (CPU) or motherboards within the case, to prevent data-bleed over between the two domains and networks.

An external digital electronic switch otherwise described as keyboard, video, mouse or (KVM), which is connected directly to both domains, the unsecured and secured, provides instant switching between the two domains without having to shut down the operating systems or loose data on either domain. Two light emitting diodes (LED) on the keyboard, video, mouse, (KVM) switch, one green and the other red, indicate which domain the authorized computer user is operating.

The unsecured domain is ON by default upon powering up the multilevel custom secured computer system when the authorized user inserts his high-level security key into the electromechanical lock of the front panel of the computer case. On this mode access to the secured domain is not possible.

The secured domain can be selected by pressing the red button on the (KVM) switch and access will be allowed only through the use of the Smart Card® reader/writer that will require the authorized user to insert his Smart Card® and subsequently his personal identification number (PIN). Without the use of the authorized user's Smart Card®, it is impossible to access the secured domain removable hard disk drive and secured network.

The multi-level custom secured computer system provides high assurance data access control and secured data processing, data storage, and data communications for data at the unsecured domain and data at the secured domain, all within a custom-built high-security computer case. Both, the unsecured domain and the secured domains having their own totally independent (CPU), data storage devices such as hard disk drives, floppy/CD-ROM drives, memory, video, network interface cards, operating systems (OS), are totally isolated and independent and operate simultaneously without allowing data to inadvertently cross over between domains.