cracking

Computer security is a field of computer science concerned with the control of risks related to computer use. The means traditionally taken to realize this objective is to attempt to create a secure computing platform, designed so that agents (users or programs) can only perform actions that have been allowed. This involves specifying and implementing a security policy. The actions in question can be reduced to operations of access, modification and deletion. Computer security can be seen as a subfield of security engine ...

Including:

• Computer security - Computer security by design
• Computer security - Early history of security by design
• Computer security - Techniques for creating secure systems
• Computer security - Capabilities vs. ACLs
• Computer security - Other uses of the term trusted
• Computer security - Notable persons in computer security

Read more here: » Computer security: Encyclopedia - Computer security

In general usage, alcohol (from Arabic al-kukhul الكحول, al meaning 'the' and kukhul meaning 'spirit', the chemical) refers almost always to ethanol, also known as grain alcohol, and often to any beverage that contains ethanol (see alcoholic beverage). This sense underlies the term alcoholism (addiction to alcohol). Other forms of alcohol are usually described with a clarifying adjective, as in isopropyl alcohol or by the suffix -ol, as in isopropanol. As a drug, com ...

Including:

• Alcohol - Structure
• Alcohol - Methanol & ethanol
• Alcohol - Uses
• Alcohol - Sources
• Alcohol - Nomenclature
• Alcohol - Systematic names
• Alcohol - Etymology
• Alcohol - Physical and chemical properties
• Alcohol - Toxicity
• Alcohol - Preparation of alcohols
• Alcohol - Laboratory
• Alcohol - Industrial
• Alcohol - Reactions of alcohols
• Alcohol - Deprotonation
• Alcohol - Nucleophilic substitution
• Alcohol - Dehydration
• Alcohol - Esterification
• Alcohol - Oxidation

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The word "security" in general usage is synonymous with "safety," but as a technical term "security" means that something not only is secure but that it has been secured. For example, In telecommunication, the term security has the following meanings: A condition that results from the establishment and maintenance of protective measures that ensure a state of inviolability from hostile acts or influences. With respect to classified matter, the condition that prevents unauthorized persons from having ...

See also:

Security, Security - Defining the word security, Security - Perceived security compared to real security, Security - Categorising security, Security - Types of security, Security - Security concepts, Security - Security standards

Read more here: » Security: Encyclopedia II - Security - Defining the word security

The following techniques can be used in engineering secure systems. These techniques, whilst useful, do not of themselves ensure security. One security maxim is "a security system is no stronger than its weakest link" Automated theorem proving and other verification tools can enable critical algorithms and code used in secure systems to be mathematically proven to meet their specifications. Thus simple microkernels can be written so that we can be sure they don't contain any bugs: eg EROS[1] and Coyotos[2]. A b ...

See also:

Computer security, Computer security - Computer security by design, Computer security - Early history of security by design, Computer security - Techniques for creating secure systems, Computer security - Capabilities vs. ACLs, Computer security - Other uses of the term trusted, Computer security - Notable persons in computer security

Read more here: » Computer security: Encyclopedia II - Computer security - Techniques for creating secure systems

There are two different approaches to security in computing. One focuses mainly on external threats, and generally treats the computer system itself as a trusted system. This philosophy is discussed in the computer insecurity article. The other, discussed in this article, regards the computer system itself as largely an untrusted system, and redesigns it to make it more secure in a number of ways. This technique enforces privilege separation, where an entity has only the privileges that are needed for its function. That way, ev ...

See also:

Computer security, Computer security - Computer security by design, Computer security - Early history of security by design, Computer security - Techniques for creating secure systems, Computer security - Capabilities vs. ACLs, Computer security - Other uses of the term trusted, Computer security - Notable persons in computer security

Read more here: » Computer security: Encyclopedia II - Computer security - Computer security by design

Coke is a solid carbonaceous residue derived from low-ash, low-sulfur bituminous coal. The volatile constituents of the coal (including water, coal-gas and coal-tar) are driven off by baking in an airless oven at temperatures as high as 1,000 degrees Celsius so that the fixed carbon and residual ash are fused together. Coke fuel - Properties & usage. Coke typically has a specific gravity in the range 1.85 - 1.9. It is highly porous, and a mass of coke has 40% greater volume than the equivalent mass of c ...

Including:

• Coke fuel - Properties & usage
• Coke fuel - History
• Coke fuel - Other varieties

Read more here: » Coke fuel: Encyclopedia - Coke fuel

The chemical compound and unsaturated hydrocarbon acetylene, also known under IUPAC nomenclature (see IUPAC nomenclature of organic chemistry) as ethyne, was discovered in 1836 by Edmund Davy, in England. Acetylene - Preparation. The principal raw materials for acetylene manufacture are calcium carbonate (limestone) and coal. The calcium carbonate is first converted into calcium oxide and the coal into coke, then the two are reacted with each other to form calcium carbide and carbon monoxide:

Including:

• Acetylene - Preparation
• Acetylene - Properties
• Acetylene - Safety and handling
• Acetylene - Reactions
• Acetylene - Uses

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Please remove this notice after the article has been expanded. Details are on this talk page or at Wikipedia:Requests for expansion. Catagenesis is a term used in petroleum geology to describe the cracking process which results in the conversion of organic kerogens into hydrocarbons. This chemical reaction is believed to be a time, temperature and pressure dependent process which creates liquid and/or gaseous hydrocarbon Hc from primary kerogen X and can be summarised using the formula: where X0 is the initial kerogen co ...

Read more here: » Catagenesis geology: Encyclopedia - Catagenesis geology

An alkane in organic chemistry is a saturated hydrocarbon without cycles, that is, an acyclic hydrocarbon in which the molecule has the maximum possible number of hydrogen atoms and so has no double bonds. Alkanes are also often known as paraffins, or collectively as the paraffin series; these terms, however, are also used to apply only to alkanes whose carbon atoms form a single, unbranched chain; when this is done, branched-chain alkanes are called isoparaffins. Alkanes are aliphatic compounds. The general formu ...

Including:

• Alkane - Isomerism
• Alkane - Nomenclature of alkanes
• Alkane - Alkanes with unbranched carbon chains
• Alkane - Alkanes with branched carbon chains
• Alkane - Trivial names
• Alkane - Occurrence
• Alkane - Purification and use
• Alkane - Preparation
• Alkane - Molecular geometry
• Alkane - Bond lengths and bond angles
• Alkane - Conformation
• Alkane - Properties
• Alkane - Physical properties
• Alkane - Chemical properties
• Alkane - Thermochemistry
• Alkane - Spectroscopic properties
• Alkane - Reactions
• Alkane - Reactions with oxygen
• Alkane - Reactions with halogens
• Alkane - Cracking and reforming
• Alkane - Other reactions
• Alkane - Hazards
• Alkane - Alkanes in nature
• Alkane - Bacteria and archaea
• Alkane - Fungi and plants
• Alkane - Animals
• Alkane - Ecological relations

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An alkene in organic chemistry is an unsaturated hydrocarbon containing at least one carbon to carbon double bond. The simplest alkenes, with only one double bond, form a homologous series, the alkenes with general formula CnH2n. The simplest alkene is C2H4, which has the common name "ethylene" and the International Union of Pure and Applied Chemistry (IUPAC) name "ethene". Alkenes are also called olefins and vinyl compounds. Alkene - Structure of AlkenesIncluding:

• Alkene - Structure of Alkenes
• Alkene - Shape of Alkenes
• Alkene - Molecular Geometry
• Alkene - Physical properties
• Alkene - Chemical properties
• Alkene - Synthesis
• Alkene - Reactions
• Alkene - Addition reactions
• Alkene - Oxidation
• Alkene - Polymerisation
• Alkene - Nomenclature of Alkenes
• Alkene - IUPAC Names
• Alkene - Common Names

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Alkylation is the transfer of an alkyl group from one molecule to another. In a standard oil refinery process, alkylation combines low-molecular-weight olefins (primarily a mixture of propylene and butylene) with isobutane in the presence of a catalyst, either sulfuric acid or hydrofluoric acid. The product is called alkylate and is composed of a mixture of high-octane, branched-chain paraffinic hydrocarbons. Alkylate is a premium gasoline blending stock because it has exceptional antiknock properties and is clean burning. The ...

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A bastion host is a network entity that provides a single entrance / exit point to the Internet. Bastion hosts are used to prevent cracking of a network by providing a barrier between private and public areas. Typically a bastion host will be configured with a firewall and provide services like web servers, DNS servers and mail servers. It may also include "victim hosts". See also: demilitarized zone ...

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Reverse engineering (RE) is the process of taking something (a mechanical device, an electrical component, a software program, etc.) apart and analyzing its workings in detail, usually with the intention to construct a new device or program that does the same thing without actually copying anything from the original. The verb form is to reverse-engineer, spelled with a hyphen. A telling analogy of RE is that the research of physical ...

Including:

• Reverse engineering - Types and applications of RE
• Reverse engineering - Reverse engineering of software
• Reverse engineering - Binary software
• Reverse engineering - Binary software: techniques

Read more here: » Reverse engineering: Encyclopedia - Reverse engineering

Biofuel is any fuel that derives from biomass — recently living organisms or their metabolic byproducts, such as manure from cows. It is a renewable energy source, unlike other natural resources such as petroleum, coal and nuclear fuels. The carbon in biofuels was recently extracted from atmospheric carbon dioxide by growing plants, so burning it does not result in a net increase of carbon dioxide in the Earth's atmosphere. As a result, biofuels are seen by many as a way to reduce the amount of carbon dioxide released into the atmosphere by using th ...

Including:

• Biofuel - Classes of Biofuels
• Biofuel - Solid
• Biofuel - Liquid
• Biofuel - Gaseous
• Biofuel - Other
• Biofuel - Energy content of Biofuel
• Biofuel - Problems and solutions
• Biofuel - International efforts

Read more here: » Biofuel: Encyclopedia - Biofuel

It is very often true that people's perception of security is not directly related to the actual security. For example, a fear of flying is much more common than a fear of driving; however, driving is generally a much more dangerous form of transport. Another side of this is a phenomenon called security theatre where ineffective security measures such as screening of airline passengers based on static databases are introduced with little real increase in security or even, according to the critics of on ...

See also:

Security, Security - Defining the word security, Security - Perceived security compared to real security, Security - Categorising security, Security - Types of security, Security - Security concepts, Security - Security standards

Read more here: » Security: Encyclopedia II - Security - Perceived security compared to real security

There is an immense literature on the analysis and categorisation of security. Part of the reason for this is that, in most security systems, it is the "weakest link in the chain" which is the most important. The situation is asymmetric since defender must cover all points of attack whilst the attacker must only identify one weak point and concentrate on that. Security - Types of security. physical security information security computing security financial security human security < ...

See also:

Security, Security - Defining the word security, Security - Perceived security compared to real security, Security - Categorising security, Security - Types of security, Security - Security concepts, Security - Security standards

Read more here: » Security: Encyclopedia II - Security - Categorising security

The term "trusted" is often applied to operating systems that meet different levels of the common criteria, some of which are discussed above as the techniques for creating secure systems. A computer industry group led by Microsoft has used the term "trusted system" to include making computer hardware that could impose restrictions on how people use their computers. The project is called the Trusted Computing ...

See also:

Computer security, Computer security - Computer security by design, Computer security - Early history of security by design, Computer security - Techniques for creating secure systems, Computer security - Capabilities vs. ACLs, Computer security - Other uses of the term trusted, Computer security - Notable persons in computer security

Read more here: » Computer security: Encyclopedia II - Computer security - Other uses of the term trusted

Within computer systems, the two fundamental means of enforcing privilege separation are access control lists (ACLs) and capabilities. The semantics of ACLs have been proven to be insecure in many situations (e.g., Confused deputy problem). It has also been shown that ACL's promise of giving access to an object to only one person can never be guaranteed in practice. Both of these problems are resolved by capabilities. This does not mean practical flaws exist in all ACL-based systems — only that the designers of certain utilities must take ...

See also:

Computer security, Computer security - Computer security by design, Computer security - Early history of security by design, Computer security - Techniques for creating secure systems, Computer security - Capabilities vs. ACLs, Computer security - Other uses of the term trusted, Computer security - Notable persons in computer security

Read more here: » Computer security: Encyclopedia II - Computer security - Capabilities vs. ACLs

Alcohol - Deprotonation. Alcohols can behave as weak acids, undergoing deprotonation. The deprotonation reaction to produce an alkoxide salt is either performed with a strong base such as sodium hydride or n-butyllithium, or with sodium or potassium metal. 2 R-OH + 2 NaH → 2 R-O-Na+ + H2↑ 2 R-OH + 2Na → 2R-O−Na+ e.g. 2 CH3CH2-OH + 2 Na → 2 CH3-CH ...

See also:

Alcohol, Alcohol - Structure, Alcohol - Primary secondary and tertiary alcohols, Alcohol - Methanol & ethanol, Alcohol - Uses, Alcohol - Sources, Alcohol - Nomenclature, Alcohol - Systematic names, Alcohol - Etymology, Alcohol - Physical and chemical properties, Alcohol - Toxicity, Alcohol - Preparation of alcohols, Alcohol - Laboratory, Alcohol - Industrial, Alcohol - Reactions of alcohols, Alcohol - Deprotonation, Alcohol - Nucleophilic substitution, Alcohol - Dehydration, Alcohol - Esterification, Alcohol - Oxidation

Read more here: » Alcohol: Encyclopedia II - Alcohol - Reactions of alcohols

Biofuel - Solid. There are many forms of solid biomass that are combustible as a fuel1 such as: Wood — see wood fuel. Straw and other dried plants such as Miscanthus. Animal waste such as poultry droppings or cattle dung. Crops such as maize, rice, soybean, peanut and cotton (usually just the husks or shells) [2], including Sugarcan ...

See also:

Biofuel, Biofuel - Classes of Biofuels, Biofuel - Solid, Biofuel - Liquid, Biofuel - Gaseous, Biofuel - Other, Biofuel - Energy content of Biofuel, Biofuel - Problems and solutions, Biofuel - International efforts

Read more here: » Biofuel: Encyclopedia II - Biofuel - Classes of Biofuels