The Biba Model or Biba Integrity Model developed by Kenneth J. Biba in 1975, [1] is a formal state transition system of computer security policy describing a set of access control rules designed to ensure data integrity. Data and subjects are grouped into ordered levels of integrity. The model is designed so that subjects may not corrupt data in a level ranked higher than the subject, or be corrupted by data from a lower level than the subject.
In general the model was developed to address integrity as the core principle, which is the direct inverse of the Bell–LaPadula model which focuses on confidentiality. [2] : 35
In general, preservation of data integrity has three goals:
This security model is directed toward data integrity (rather than confidentiality) and is characterized by the phrase: "read up, write down". This is in contrast to the Bell-LaPadula model which is characterized by the phrase "read down, write up".
In the Biba model, users can only create content at or below their own integrity level (a monk may write a prayer book that can be read by commoners, but not one to be read by a high priest). Conversely, users can only view content at or above their own integrity level (a monk may read a book written by the high priest, but may not read a pamphlet written by a lowly commoner). Another analogy to consider is that of the military chain of command. A General may write orders to a Colonel, who can issue these orders to a Major. In this fashion, the General's original orders are kept intact and the mission of the military is protected (thus, "read up" integrity). Conversely, a Private can never issue orders to his Sergeant, who may never issue orders to a Lieutenant, also protecting the integrity of the mission ("write down").
The Biba model defines a set of security rules, the first two of which are similar to the Bell–LaPadula model. These first two rules are the reverse of the Bell–LaPadula rules:
Simple Network Management Protocol (SNMP) is an Internet Standard protocol for collecting and organizing information about managed devices on IP networks and for modifying that information to change device behaviour. Devices that typically support SNMP include cable modems, routers, switches, servers, workstations, printers, and more.
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.
In computer security, an access-control list (ACL) is a list of permissions associated with a system resource (object). An ACL specifies which users or system processes are granted access to objects, as well as what operations are allowed on given objects. Each entry in a typical ACL specifies a subject and an operation. For instance, if a file object has an ACL that contains (Alice: read,write; Bob: read), this would give Alice permission to read and write the file and give Bob permission only to read it.
In computer systems security, role-based access control (RBAC) or role-based security is an approach to restricting system access to authorized users. It is an approach to implement mandatory access control (MAC) or discretionary access control (DAC).
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.
Rule-set-based access control (RSBAC) is an open source access control framework for current Linux kernels, which has been in stable production use since January 2000.
In computer security, mandatory access control (MAC) refers to a type of access control by which the operating system or database constrains the ability of a subject or initiator to access or generally perform some sort of operation on an object or target. In the case of operating systems, a subject is usually a process or thread; objects are constructs such as files, directories, TCP/UDP ports, shared memory segments, IO devices, etc. Subjects and objects each have a set of security attributes. Whenever a subject attempts to access an object, an authorization rule enforced by the operating system kernel examines these security attributes and decides whether the access can take place. Any operation by any subject on any object is tested against the set of authorization rules to determine if the operation is allowed. 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.
A computer security policy defines the goals and elements of an organization's computer systems. The definition can be highly formal or informal. Security policies are enforced by organizational policies or security mechanisms. A technical implementation defines whether a computer system is secure or insecure. These formal policy models can be categorized into the core security principles of Confidentiality, Integrity, and Availability. For example, the Bell-La Padula model is a confidentiality policy model, whereas the Biba model is an integrity policy model.
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. One is to refer to a system that is adequate to protect itself from subversion and has robust mechanisms to separate information domains, that is, trustworthy. Another context is to refer to an application of a computer that will require the computer to be strong enough to protect itself from subversion and possess adequate mechanisms to separate information domains, that is, a system we must trust. This distinction is important because systems that need to be trusted are not necessarily trustworthy.
The Clark–Wilson integrity model provides a foundation for specifying and analyzing an integrity policy for a computing system.
The Graham–Denning model is a computer security model that shows how subjects and objects should be securely created and deleted. It also addresses how to assign specific access rights. It is mainly used in access control mechanisms for distributed systems. There are three main parts to the model: A set of subjects, a set of objects, and a set of eight rules. A subject may be a process or a user that makes a request to access a resource. An object is the resource that a user or process wants to access.
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:
A computer security model is a scheme for specifying and enforcing security policies. A security model may be founded upon a formal model of access rights, a model of computation, a model of distributed computing, or no particular theoretical grounding at all. A computer security model is implemented through a computer security policy.
In the fields of physical security and information security, the high-water mark for access control was introduced by Clark Weissmann in 1969. It pre-dates the Bell–LaPadula security model, whose first volume appeared in 1972.
Multi categories security (MCS) is an access control method in Security-Enhanced Linux that uses categories attached to objects (files) and granted to subjects at the operating system level. The implementation in Fedora Core 5 is advisory because there is nothing stopping a process from increasing its access. The eventual aim is to make MCS a hierarchical mandatory access control system. Currently, MCS controls access to files and to ptrace or kill processes. It has not yet decided what level of control it should have over access to directories and other file system objects. It is still evolving.
In computer security, lattice-based access control (LBAC) is a complex access control model based on the interaction between any combination of objects and subjects.
In computer science, an access control matrix or access matrix is an abstract, formal security model of protection state in computer systems, that characterizes the rights of each subject with respect to every object in the system. It was first introduced by Butler W. Lampson in 1971.
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.
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 computer security, general access control includes identification, authorization, authentication, access approval, and audit. A more narrow definition of access control would cover only access approval, whereby the system makes a decision to grant or reject an access request from an already authenticated subject, based on what the subject is authorized to access. Authentication and access control are often combined into a single operation, so that access is approved based on successful authentication, or based on an anonymous access token. Authentication methods and tokens include passwords, biometric scans, physical keys, electronic keys and devices, hidden paths, social barriers, and monitoring by humans and automated systems.