US 5,859,966 A · Security system for computer systems

Abstract

A security system for a computer system imposes specific limitations on who has access to the computer system and to exactly what operations and data. Viruses are securely contained and prevented from expanding into areas where they can destroy stored programs or data. Viruses are also prevented from being introduced or executed in a large number of instances. The totality of computer functions is broken up into a set of events with an associated set of capabilities and different capabilities are assigned to each user depending on the particular job which that user is to do on the computer system. Also, security labels are placed on each data file and other system resources, and on each process. Further, a range of hierarchy/category labels (MAC labels) is assigned to each process to define a sub-lattice in which special capabilities can apply. Further, the hierarchy of labels is divided into a small number (for example 3) of regions, and a process operating in one region is generally not allowed to cross over into another region. Further, an owner of a data file is allowed to place restrictions on the file so that only users who posses certain privileges can gain access to the file.

Claims13

Dependent claims

A security control method for a computer system, said method comprising steps of:

(a) storing in a database of said computer system and in the computer system itself security policies;
(b) continually accessing said database and the computer system during use thereof in order to determine the specific policy stored therein with respect to a particular subject presently using the computer system;
and
(c) allowing the subject access to said computer system only to the extent allowed by the results of step (b);
wherein said database contains:
a subject inheritable capability set containing a plurality of capabilities which a subject can pass on to future program executions,
a subject bounding capability set containing an absolute upper limit on all capabilities assigned to a subject, and
further wherein, according to the security policy stored in said database and the computer system, a subject is prohibited from passing on capabilities in its subject inheritable capability set when such capabilities are not included in the subject's bounding capability set.

5 more elements

Dependencies are inferred from the claim text.

Security system for computer systems

Life of this patent

Security system for computer systems

Life of this patent

Abstract

Claims13