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Bell–LaPadula Model
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 (e.g., "Top Secret"), down to the least sensitive (e.g., "Unclassified" or "Public"). The Bell–LaPadula model is an example of a model where there is no clear distinction between protection and security. Features The Bell–LaPadula model focuses on data confidentiality and controlled access to classified information, in contrast to the Biba Integrity Model which describes rules for the protection of data integrity. In ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Finite State Machine
A finite-state machine (FSM) or finite-state automaton (FSA, plural: ''automata''), finite automaton, or simply a state machine, is a mathematical model of computation. It is an abstract machine that can be in exactly one of a finite number of '' states'' at any given time. The FSM can change from one state to another in response to some inputs; the change from one state to another is called a ''transition''. An FSM is defined by a list of its states, its initial state, and the inputs that trigger each transition. Finite-state machines are of two types— deterministic finite-state machines and non-deterministic finite-state machines. A deterministic finite-state machine can be constructed equivalent to any non-deterministic one. The behavior of state machines can be observed in many devices in modern society that perform a predetermined sequence of actions depending on a sequence of events with which they are presented. Simple examples are vending machines, which dispense p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mathematical Induction
Mathematical induction is a method for proving that a statement ''P''(''n'') is true for every natural number ''n'', that is, that the infinitely many cases ''P''(0), ''P''(1), ''P''(2), ''P''(3), ... all hold. Informal metaphors help to explain this technique, such as falling dominoes or climbing a ladder: A proof by induction consists of two cases. The first, the base case, proves the statement for ''n'' = 0 without assuming any knowledge of other cases. The second case, the induction step, proves that ''if'' the statement holds for any given case ''n'' = ''k'', ''then'' it must also hold for the next case ''n'' = ''k'' + 1. These two steps establish that the statement holds for every natural number ''n''. The base case does not necessarily begin with ''n'' = 0, but often with ''n'' = 1, and possibly with any fixed natural number ''n'' = ''N'', establishing the truth of the statement for all natu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Graham–Denning Model
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. Features This model addresses the security issues associated with how to define a set of basic rights on how specific subjects can execute security functions on an object. The model has eight basic protection rules (actions) that outline: * How to securely create an object. * How to securely create a subject. * How to securely delete an object. * How to securely delete a subject. * How to securely provide the read access right. * How to securely provide the grant access r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Discretionary Access Control
In computer security, discretionary access control (DAC) is a type of access control defined by the Trusted Computer System Evaluation Criteria (TCSEC) as a means of restricting access to objects based on the identity of subjects and/or groups to which they belong. The controls are discretionary in the sense that a subject with a certain access permission is capable of passing that permission (perhaps indirectly) on to any other subject (unless restrained by mandatory access control). Discretionary access control is commonly discussed in contrast to mandatory access control (MAC). Occasionally, a system as a whole is said to have "discretionary" or "purely discretionary" access control when that system lacks mandatory access control. On the other hand, systems can implement both MAC and DAC simultaneously, where DAC refers to one category of access controls that subjects can transfer among each other, and MAC refers to a second category of access controls that imposes constraint ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle Of Least Privilege
In information security, computer science, and other fields, the principle of least privilege (PoLP), also known as the principle of minimal privilege (PoMP) or the principle of least authority (PoLA), requires that in a particular abstraction layer of a computing environment, every module (such as a process, a user, or a program, depending on the subject) must be able to access only the information and resources that are necessary for its legitimate purpose. Details The principle means giving a user account or process only those privileges which are essential to perform its intended function. For example, a user account for the sole purpose of creating backups does not need to install software: hence, it has rights only to run backup and backup-related applications. Any other privileges, such as installing new software, are blocked. The principle applies also to a personal computer user who usually does work in a normal user account, and opens a privileged, password protected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Database Management System
In computing, a database is an organized collection of data stored and accessed electronically. Small databases can be stored on a file system, while large databases are hosted on computer clusters or cloud storage. The design of databases spans formal techniques and practical considerations, including data modeling, efficient data representation and storage, query languages, security and privacy of sensitive data, and distributed computing issues, including supporting concurrent access and fault tolerance. A database management system (DBMS) is the software that interacts with end users, applications, and the database itself to capture and analyze the data. The DBMS software additionally encompasses the core facilities provided to administer the database. The sum total of the database, the DBMS and the associated applications can be referred to as a database system. Often the term "database" is also used loosely to refer to any of the DBMS, the database system or an applicati ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boolean Policy
Any kind of logic, function, expression, or theory based on the work of George Boole is considered Boolean. Related to this, "Boolean" may refer to: * Boolean data type, a form of data with only two possible values (usually "true" and "false") * Boolean algebra, a logical calculus of truth values or set membership * Boolean algebra (structure), a set with operations resembling logical ones * Boolean domain, a set consisting of exactly two elements whose interpretations include ''false'' and ''true'' * Boolean circuit, a mathematical model for digital logical circuits. * Boolean expression, an expression in a programming language that produces a Boolean value when evaluated * Boolean function, a function that determines Boolean values or operators * Boolean model (probability theory), a model in stochastic geometry * Boolean network, a certain network consisting of a set of Boolean variables whose state is determined by other variables in the network * Boolean processor, a 1-bit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Covert Channel
In computer security, a covert channel is a type of attack that creates a capability to transfer information objects between processes that are not supposed to be allowed to communicate by the computer security policy. The term, originated in 1973 by Butler Lampson, is defined as channels "not intended for information transfer at all, such as the service program's effect on system load," to distinguish it from ''legitimate'' channels that are subjected to access controls by COMPUSEC. Characteristics A covert channel is so called because it is hidden from the access control mechanisms of secure operating systems since it does not use the legitimate data transfer mechanisms of the computer system (typically, read and write), and therefore cannot be detected or controlled by the security mechanisms that underlie secure operating systems. Covert channels are exceedingly hard to install in real systems, and can often be detected by monitoring system performance. In addition, they su ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brewer And Nash Model
The Brewer and Nash model was constructed to provide information security access controls that can change dynamically. This security model, also known as the Chinese wall model, was designed to provide controls that mitigate conflict of interest in commercial organizations and is built upon an information flow model. In the Brewer and Nash model, no information can flow between the subjects and objects in a way that would create a conflict of interest. This model is commonly used by consulting and accounting firms. For example, once a consultant accesses data belonging to Acme Ltd, a consulting client, they may no longer access data to any of Acme's competitors. In this model, the same consulting firm can have clients that are competing with Acme Ltd while advising Acme Ltd. This model uses the principle of data isolation within each conflict class of data to keep users out of potential conflict of interest situations. Because company relationships change all the time, dynami ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Clark–Wilson Model
The Clark–Wilson integrity model provides a foundation for specifying and analyzing an integrity policy for a computing system. The model is primarily concerned with formalizing the notion of information integrity. Information integrity is maintained by preventing corruption of data items in a system due to either error or malicious intent. An integrity policy describes how the data items in the system should be kept valid from one state of the system to the next and specifies the capabilities of various principals in the system. The model uses security labels to grant access to objects via transformation procedures and a restricted interface model. Origin The model was described in a 1987 paper (''A Comparison of Commercial and Military Computer Security Policies'') by David D. Clark and David R. Wilson. The paper develops the model as a way to formalize the notion of information integrity, especially as compared to the requirements for multilevel security (MLS) systems ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mandatory Access Control
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 (aka ''policy'') 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 objec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
