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Secure Hardware Architecture

Secure Hardware Architecture focuses on the physical computer hardware required to have a secure system. The hardware must provide confidentiality, integrity, and availability for processes, data, and users.

The System Unit and Motherboard

The system unit is the computer’s case: it contains all the internal electronic computer components, including motherboard, internal disk drives, and power supply. The motherboard contains hardware including the CPU, memory slots, firmware, and peripheral slots such as PCI (Peripheral Component Interconnect) slots. The keyboard unit is the external keyboard.

The Computer Bus

A computer bus, shown in FIG. 4.8, is the primary communication channel on a computer system. Communication between the CPU, memory, and input/output devices such as keyboard, mouse, and display occur via the bus.

FIG. 4.8 Simplified computer bus

Northbridge and Southbridge

Some computer designs use two buses: a northbridge and southbridge. The names derive from the visual design, usually shown with the northbridge on top and the southbridge on the bottom, as shown in Fig. 4.9. The northbridge, also called the Memory Controller Hub (MCH), connects the CPU to RAM and video memory. The southbridge, also called the I/O Controller Hub (ICH), connects input/output (I/O) devices, such as disk, keyboard, mouse, CD drive, and USB ports. The northbridge is directly connected to the CPU and is faster than the southbridge.

FIG. 4.9 Northbridge and southbridge design.