A personal computer a smartphone, a tablet, a web server or a cloud server configured for connection to a network of computers or system on a microchip including one or more buffer zones excluding circuitry and two or more zones, each including circuitry. The one or more buffer zones form one or more boundaries separating the zones including circuitry. At least a first of the zones including circuitry includes at least one public unit with a microprocessor and a network communication component. At least a second of the zones including circuitry includes at least one private unit with at least a separate, private network connection and a microprocessor that is a central controller of the computer. The public unit and the at least one private unit can be connected by at least one secure control bus that is isolated from input from a public network.