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Separation Of Protection And Security
In computer sciences, the separation of protection and security is a design choice. Wulf et al. identified protection as a mechanism and security as a policy,Wulf 74 pp.337-345 therefore making the protection-security distinction a particular case of the separation of mechanism and policy principle. Many frameworks consider both as security controls of varying types. For example, protection mechanisms would be considered technical controls, while a policy would be considered an administrative control. Overview The adoption of this distinction in a computer architecture usually means that protection is provided as a fault tolerance mechanism by hardware/firmware and kernel, whereas the operating system and applications implement their security policies. In this design, security policies rely therefore on the protection mechanisms and on additional cryptography techniques. The major hardware approachSwift 2005 p.26 for security or protection is the use of hierarchical prote ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Sciences
Computer science is the study of computation, automation, and information. Computer science spans theoretical disciplines (such as algorithms, theory of computation, information theory, and automation) to practical disciplines (including the design and implementation of hardware and software). Computer science is generally considered an area of academic research and distinct from computer programming. Algorithms and data structures are central to computer science. The theory of computation concerns abstract models of computation and general classes of problems that can be solved using them. The fields of cryptography and computer security involve studying the means for secure communication and for preventing security vulnerabilities. Computer graphics and computational geometry address the generation of images. Programming language theory considers different ways to describe computational processes, and database theory concerns the management of repositories of data. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ring (computer Security)
In computer science, hierarchical protection domains, often called protection rings, are mechanisms to protect data and functionality from faults (by improving fault tolerance) and malicious behavior (by providing computer security). Computer operating systems provide different levels of access to resources. A protection ring is one of two or more hierarchical ''levels'' or ''layers'' of privilege within the architecture of a computer system. This is generally hardware-enforced by some CPU architectures that provide different CPU modes at the hardware or microcode level. Rings are arranged in a hierarchy from most privileged (most trusted, usually numbered zero) to least privileged (least trusted, usually with the highest ring number). Ring 0 is the level with the most privileges and allows direct interaction with the physical hardware such as certain CPU functionality and chips on the motherboard. Special call gates between rings are provided to allow an outer ring to ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Computer Security Policy
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''. Formal description If a system is regarded as a finite-state automaton with a set of transitions (operations) that change the system's state, then a ''security policy'' can be seen as a statement that partitions these states into authorized and unauthorized ones. Given this simple definition, one can define a ''secure system'' as one that starts in an authorized state and will never enter an unauthorize ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capability-based Addressing
In computer science, capability-based addressing is a scheme used by some computers to control access to memory as an efficient implementation of capability-based security. Under a capability-based addressing scheme, pointers are replaced by protected objects (called capabilities) that can be created only through the use of privileged instructions which may be executed only by either the kernel or some other privileged process authorised to do so. Thus, a kernel can limit application code and other subsystems access to the minimum necessary portions of memory (and disable write access where appropriate), without the need to use separate address spaces and therefore require a context switch when an access occurs. Practical implementations Two techniques are available for implementation: *Require capabilities to be stored in a particular area of memory that cannot be written to by the process that will use them. For example, the Plessey System 250 required that all capabilities be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Constraints Security Model
Constraint may refer to: * Constraint (computer-aided design), a demarcation of geometrical characteristics between two or more entities or solid modeling bodies * Constraint (mathematics), a condition of an optimization problem that the solution must satisfy * Constraint (classical mechanics), a relation between coordinates and momenta * Constraint (information theory), the degree of statistical dependence between or among variables * ''Constraints'' (journal), a scientific journal * Constraint (database), a concept in relational database See also * Biological constraints, factors which make populations resistant to evolutionary change * Carrier's constraint * Constrained optimization, in finance, linear programming, economics and cost modeling * Constrained writing, in literature * Constraint algorithm, such as SHAKE, or LINCS * Constraint satisfaction, in computer science * Finite domain constraint * First class constraint in Hamiltonian mechanics * Integrity constraints * L ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Strong Dependency
Strong may refer to: Education * The Strong, an educational institution in Rochester, New York, United States * Strong Hall (Lawrence, Kansas), an administrative hall of the University of Kansas * Strong School, New Haven, Connecticut, United States, an overflow school for district kindergartners and first graders Music Albums * ''Strong'' (Anette Olzon album), 2021 * ''Strong'' (Arrested Development album), 2010 * ''Strong'' (Michelle Wright album), 2013 * ''Strong'' (Thomas Anders album), 2010 * ''Strong'' (Tracy Lawrence album), 2004 * ''Strong'', a 2000 album by Clare Quilty Songs * "Strong" (London Grammar song), 2013 * "Strong" (One Direction song), 2013 * "Strong" (Robbie Williams song), 1998 * "Strong", a song by After Forever from ''Remagine'' * "Strong", a song by Audio Adrenaline from '' Worldwide'' * "Strong", a song by LeAnn Rimes from '' Whatever We Wanna'' * "Strong", a song by London Grammar from ''If You Wait'' * "Strong", a song by Will Hoge from '' Ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Information Flow (information Theory)
Information flow in an information theoretical context is the transfer of information from a variable x to a variable y in a given process. Not all flows may be desirable; for example, a system should not leak any confidential information (partially or not) to public observers--as it is a violation of privacy on an individual level, or might cause major loss on a corporate level. Introduction Securing the data manipulated by computing systems has been a challenge in the past years. Several methods to limit the information disclosure exist today, such as access control lists, firewalls, and cryptography. However, although these methods do impose limits on the information that is released by a system, they provide no guarantees about information ''propagation''.Andrei Sabelfeld and Andrew C. Myers. Language-Based Information-Flow Security. IEEE Journal on Selected Areas in Communications, 21(1), Jan. 2003. For example, access control lists of file systems prevent unauthorized ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
High-water Mark (computer Security)
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. Under high-water mark, any object less than the user's security level can be opened, but the object is relabeled to reflect the highest security level currently open, hence the name. The practical effect of the high-water mark was a gradual movement of all objects towards the highest security level in the system. If user A is writing a CONFIDENTIAL document, and checks the unclassified dictionary, the dictionary becomes CONFIDENTIAL. Then, when user B is writing a SECRET report and checks the spelling of a word, the dictionary becomes SECRET. Finally, if user C is assigned to assemble the daily intelligence briefing at the TOP SECRET level, reference to the dictionary makes the dictionary TOP SECRET, too. Low-water mark Low-water mark is an extension ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Filter (security)
Filter, filtering or filters may refer to: Science and technology Computing * Filter (higher-order function), in functional programming * Filter (software), a computer program to process a data stream * Filter (video), a software component that performs some operation on a multimedia stream * Email filtering, the processing of email to organize it according to specified criteria * Content-control software also known as an Internet filter * Wordfilter, a script typically used on Internet forums or chat rooms * Berkeley Packet Filter, filter expression used in the qualification of network data * DSL filter, a low-pass filter installed between analog devices and a telephone line * Helicon Filter, a raster graphics editor * Filter (large eddy simulation), a mathematical operation intended to remove a range of small scales from the solution to the Navier-Stokes equations * Kalman filter, an approximating algorithm in optimal control applications and problems Device * Filte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Take-grant
The take-grant protection model is a formal model used in the field of computer security to establish or disprove the safety of a given computer system that follows specific rules. It shows that even though the question of safety is in general undecidable, for specific systems it is decidable in linear time. The model represents a system as directed graph, where vertices are either subjects or objects. The edges between them are labeled and the label indicates the rights that the source of the edge has over the destination. Two rights occur in every instance of the model: ''take'' and ''grant''. They play a special role in the graph rewriting rules describing admissible changes of the graph. There are a total of four such rules: * ''take rule'' allows a subject to take rights of another object (add an edge originating at the subject) * ''grant rule'' allows a subject to grant own rights to another object (add an edge terminating at the subject) * ''create rule'' allows a subject ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
UCLA Data Secure Unix
The University of California, Los Angeles (UCLA) is a public land-grant research university in Los Angeles, California. UCLA's academic roots were established in 1881 as a teachers college then known as the southern branch of the California State Normal School (now San José State University). This school was absorbed with the official founding of UCLA as the Southern Branch of the University of California in 1919, making it the second-oldest of the 10-campus University of California system (after UC Berkeley). UCLA offers 337 undergraduate and graduate degree programs in a wide range of disciplines, enrolling about 31,600 undergraduate and 14,300 graduate and professional students. UCLA received 174,914 undergraduate applications for Fall 2022, including transfers, making the school the most applied-to university in the United States. The university is organized into the College of Letters and Science and 12 professional schools. Six of the schools offer undergradua ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
