Evaluatable high-assurance guard for security applications

A computer-readable medium having computer-executable instructions for performing a method for providing a high-assurance guard in a partitioned processing system, the partitioned processing system including a first input/output partition, a guard function partition and a second input/output partition, said method comprising:

• receiving a data packet from the first input/output partition of the partitioned processing system via a first I/O interface, wherein the data Packet is received by a first inter-partition communication mediator component;
• determining if the data packet is well-formed as defined by an interface control document;
• forwarding the data packet to the second input/output partition of the partitioned processing system and to a second I/O interface only when the data packet is well-formed, wherein the data packet is forwarded to the second input/output partition from a second inter-partition communication mediator component;
• forwarding audit data from the first inter-partition communication mediator component to an audit partition of the partitioned processing system, wherein access to each inter-partition communication mediator component is controlled by a mutual exclusion synchronization mechanism;
• limiting access to each inter-partition communication mediator component and each mutual exclusion synchronization mechanism to a partition included in the group consisting of the first input/output partition, the second input/output partition, the guard function partition and the audit partition;
• and
• ensuring that only one partition of the partitioned processing system is active at any one time.