In physical security and information security, access control (AC) is the selective restriction of access to a place or other resource, while access management describes the process. The act of accessing may mean consuming, entering, or using. Permission to access a resource is called authorization.
In the security engineering subspecialty of computer science, a trusted system is one that is relied upon to a specified extent to enforce a specified security policy. This is equivalent to saying that a trusted system is one whose failure would break a security policy.
Classified information is material that a government body deems to be sensitive information that must be protected. Access is restricted by law or regulation to particular groups of people with the necessary security clearance and need to know. Mishandling of the material can incur criminal penalties.
The Bell–LaPadula model (BLP) is a state machine model used for enforcing access control in government and military applications. It was developed by David Elliott Bell, and Leonard J. LaPadula, subsequent to strong guidance from Roger R. Schell, to formalize the U.S. Department of Defense (DoD) multilevel security (MLS) policy. The model is a formal state transition model of computer security policy that describes a set of access control rules which use security labels on objects and clearances for subjects. Security labels range from the most sensitive, down to the least sensitive.
In computer security, mandatory access control (MAC) refers to a type of access control by which a secured environment constrains the ability of a subject or initiator to access or modify on an object or target. In the case of operating systems, the subject is a process or thread, while objects are files, directories, TCP/UDP ports, shared memory segments, or IO devices. Subjects and objects each have a set of security attributes. Whenever a subject attempts to access an object, the operating system kernel examines these security attributes, examines the authorization rules in place, and decides whether to grant access. A database management system, in its access control mechanism, can also apply mandatory access control; in this case, the objects are tables, views, procedures, etc.
Multilevel security or multiple levels of security (MLS) is the application of a computer system to process information with incompatible classifications, permit access by users with different security clearances and needs-to-know, and prevent users from obtaining access to information for which they lack authorization. There are two contexts for the use of multilevel security.
The Evaluation Assurance Level of an IT product or system is a numerical grade assigned following the completion of a Common Criteria security evaluation, an international standard in effect since 1999. The increasing assurance levels reflect added assurance requirements that must be met to achieve Common Criteria certification. The intent of the higher levels is to provide higher confidence that the system's principle security features are reliably implemented. The EAL level does not measure the security of the system itself, it simply states at what level the system was tested.
The National Security Agency took over responsibility for all US government encryption systems when it was formed in 1952. The technical details of most NSA-approved systems are still classified, but much more about its early systems have become known and its most modern systems share at least some features with commercial products.
The Clark–Wilson integrity model provides a foundation for specifying and analyzing an integrity policy for a computing system.
Redaction or sanitization is the process of removing sensitive information from a document so that it may be distributed to a broader audience. It is intended to allow the selective disclosure of information. Typically, the result is a document that is suitable for publication or for dissemination to others rather than the intended audience of the original document.
Generally, security modes refer to information systems security modes of operations used in mandatory access control (MAC) systems. Often, these systems contain information at various levels of security classification. The mode of operation is determined by:
The United States government classification system is established under Executive Order 13526, the latest in a long series of executive orders on the topic of classified information beginning in 1951. Issued by President Barack Obama in 2009, Executive Order 13526 replaced earlier executive orders on the topic and modified the regulations codified to 32 C.F.R. 2001. It lays out the system of classification, declassification, and handling of national security information generated by the U.S. government and its employees and contractors, as well as information received from other governments.
Multiple single-level or multi-security level (MSL) is a means to separate different levels of data by using separate computers or virtual machines for each level. It aims to give some of the benefits of multilevel security without needing special changes to the OS or applications, but at the cost of needing extra hardware.
Classified information in the United Kingdom is a system used to protect information from intentional or inadvertent release to unauthorised readers. The system is organised by the Cabinet Office and is implemented throughout central and local government and critical national infrastructure. The system is also used by private sector bodies that provide services to the public sector.
The XTS-400 is a multilevel secure computer operating system. It is multiuser and multitasking that uses multilevel scheduling in processing data and information. It works in networked environments and supports Gigabit Ethernet and both IPv4 and IPv6.
Solaris Trusted Extensions is a set of security extensions incorporated in the Solaris 10 operating system by Sun Microsystems, featuring a mandatory access control model. It succeeds Trusted Solaris, a family of security-evaluated operating systems based on earlier versions of Solaris.
A High Assurance Guard (HAG) is a multilevel security computer device which is used to communicate between different security domains, such as NIPRNet to SIPRNet. A HAG is one example of a Controlled Interface between security levels. HAGs are approved through the Common Criteria process.
Trusted Computer System Evaluation Criteria (TCSEC) is a United States Government Department of Defense (DoD) standard that sets basic requirements for assessing the effectiveness of computer security controls built into a computer system. The TCSEC was used to evaluate, classify, and select computer systems being considered for the processing, storage, and retrieval of sensitive or classified information.
In information security, a guard is a device or system for allowing computers on otherwise separate networks to communicate, subject to configured constraints. In many respects a guard is like a firewall and guards may have similar functionality to a gateway.