Multilevel security port methods, apparatuses, and computer program products

A multilevel port system on a computer operating under a multilevel operating system to permit contemporaneously opening a plurality of sockets having the same port number while meeting the requirements of an appropriate security policy, thus allowing third party applications to run as if they were unimpeded by the security policy, and methods thereby. The computer system having an operating system adhering to an access control security mechanism. Such systems include government systems wherein a hierarchy of security classification levels are defined (e.g., top secret, secret, classified, unclassified), and commercial systems. Sensitivity labels pursuant to an access control security mechanism include at least hierarchical security classifications, and may include non-hierarchical categories or compartments which represent distinct areas of information in a system. A port is characterized by a port number and a sensitivity label thus permitting opening a plurality of ports having identical port numbers and unique sensitivity labels.