System for extending Multiple Independent Levels of Security (MILS) partitioning to input/output (I/O) devices

The present invention is a system for providing Multiple Independent Levels of Security (MILS) partitioning. The system includes a memory, a bus controller communicatively coupled to the memory via a memory bus, and a MILS controller communicatively coupled to the bus controller via a host-side bus, the MILS controller configured for monitoring and controlling system transactions. The system further includes a plurality of input/output (I/O) devices communicatively coupled to the MILS controller via a plurality of corresponding device-side buses. The system further includes a MILS separation kernel configured for mapping regions of the memory to a plurality of user partitions. Each I/O device included in the plurality of I/O devices is allocated to a partition included in the plurality of partitions and is isolated from MILS separation kernel space. The MILS separation kernel is configured for guaranteeing isolation of the partitions of the memory. The system further includes a processor connected to the bus controller via a processor front-side bus. The MILS controller is configured for extending MILS partitioning to the plurality of I/O devices.