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Secure Attention Key
A secure attention key (SAK), special attention key, or secure attention sequence (SAS) is a special key, key combination or sequence to be pressed on a computer keyboard before a login screen which must, to the user, be completely trustworthy. The operating system kernel, which interacts directly with the hardware, or init system is able to detect whether the secure attention key has been pressed. When this event is detected, the trusted login processing is started. The secure attention key is designed to make login spoofing impossible, as the kernel will suspend any program, including those masquerading as the computer's login process, before starting a trustable login operation. Examples Some examples are: * : Introduced in systemd v257 as a more reliable SAK for Linux distributions but may require support from the currently running desktop environment. It is implemented as of gdm (GNOME display manager) 47. * on X Window System immediately kills the X server (although ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Microsoft
Microsoft Corporation is an American multinational corporation and technology company, technology conglomerate headquartered in Redmond, Washington. Founded in 1975, the company became influential in the History of personal computers#The early 1980s and home computers, rise of personal computers through software like Windows, and the company has since expanded to Internet services, cloud computing, video gaming and other fields. Microsoft is the List of the largest software companies, largest software maker, one of the Trillion-dollar company, most valuable public U.S. companies, and one of the List of most valuable brands, most valuable brands globally. Microsoft was founded by Bill Gates and Paul Allen to develop and sell BASIC interpreters for the Altair 8800. It rose to dominate the personal computer operating system market with MS-DOS in the mid-1980s, followed by Windows. During the 41 years from 1980 to 2021 Microsoft released 9 versions of MS-DOS with a median frequen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GNOME
A gnome () is a mythological creature and diminutive spirit in Renaissance magic and alchemy, introduced by Paracelsus in the 16th century and widely adopted by authors, including those of modern fantasy literature. They are typically depicted as small humanoids who live underground. Gnome characteristics are reinterpreted to suit various storytellers and artists. Paracelsus's gnome is recognized to have derived from the German miners' legend about or , the "metallurgical or mineralogical demon", according to Georg Agricola (1530), also called (literal Latinization of ''Bergmännlein'', "mountain manikin") by Agriocola in a later work (1549), and described by other names such as (sing. ; Latinization of German ). Agricola recorded that, according to the legends of that profession, these mining spirits acted as miming and laughing pranksters who sometimes threw pebbles at miners, but could also reward them by depositing a rich vein of silver ore. Paracelsus also called ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Break Key
The Break key (or the symbol ⎊) of a computer keyboard refers to breaking a Telegraphy, telegraph circuit and originated with 19th century practice. In modern usage, the key has no well-defined purpose, but while this is the case, it can be used by software for miscellaneous tasks, such as to switch between multiple login sessions, to terminate a program, or to interrupt a modem connection. Because the break function is usually combined with the pause function on one key since the introduction of the IBM Model M 101-key keyboard in 1985, the Break key is also called the Pause key. It can be used to pause some computer games. History A standard telegraph circuit connects all the keys, Telegraph sounder, sounders and batteries in a single series loop. Thus the sounders actuate only when both keys are down (closed, also known as "mark and space, marking" — after the ink marks made on paper tape by early printing telegraphs). So the receiving operator has to hold their key do ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Control-Alt-Delete
Control-Alt-Delete (often abbreviated to Ctrl+Alt+Del and sometimes called the "three-finger salute" or "Security Keys") is a computer keyboard command on IBM PC compatible computers, invoked by pressing the Delete key while holding the Control and Alt keys: . The function of the key combination differs depending on the context but it generally interrupts or facilitates interrupting a function. For instance, in pre-boot environment (before an operating system starts) or in MS-DOS, Windows 3.0 and earlier versions of Windows or OS/2, the key combination reboots the computer. Starting with Windows 95, the key combination invokes a task manager or security related component that facilitates ending a Windows session or killing a frozen application. History The soft reboot function via keyboard was originally designed by David Bradley. Bradley, as the chief engineer of the IBM PC project and developer of the machine's ROM-BIOS, had originally used , but found it was too ea ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
PLATO (computer System)
PLATO (Programmed Logic for Automatic Teaching Operations), also known as Project Plato and Project PLATO, was the first generalized computer-assisted instruction system. Starting in 1960, it ran on the University of Illinois's ILLIAC I computer. By the late 1970s, it supported several thousand graphics terminals distributed worldwide, running on nearly a dozen different networked mainframe computers. Many modern concepts in multi-user computing were first developed on PLATO, including forums, message boards, online testing, email, chat rooms, picture languages, instant messaging, remote screen sharing, and multiplayer video games. PLATO was designed and built by the University of Illinois and functioned for four decades, offering coursework (elementary through university) to UIUC students, local schools, prison inmates, and other universities. Courses were taught in a range of subjects, including Latin, chemistry, education, music, Esperanto, and primary mathematics. Th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kernel
Kernel may refer to: Computing * Kernel (operating system), the central component of most operating systems * Kernel (image processing), a matrix used for image convolution * Compute kernel, in GPGPU programming * Kernel method, in machine learning * Kernelization, a technique for designing efficient algorithms ** Kernel, a routine that is executed in a vectorized loop, for example in general-purpose computing on graphics processing units *KERNAL, the Commodore operating system Mathematics Objects * Kernel (algebra), a general concept that includes: ** Kernel (linear algebra) or null space, a set of vectors mapped to the zero vector ** Kernel (category theory), a generalization of the kernel of a homomorphism ** Kernel (set theory), an equivalence relation: partition by image under a function ** Difference kernel, a binary equalizer: the kernel of the difference of two functions Functions * Kernel (geometry), the set of points within a polygon from which the whole polygon boundary ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trusted Computer System Evaluation Criteria
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. The TCSEC, frequently referred to as the Orange Book, is the centerpiece of the DoD ''Rainbow Series'' publications. Initially issued in 1983 by the National Computer Security Center (NCSC), an arm of the National Security Agency, and then updated in 1985, TCSEC was eventually replaced by the Common Criteria international standard, originally published in 2005. History By the late 1960s, government agencies, like other computer users, had gone far in the transition from batch processing to multiuser and time-sharing systems. The US Department of Defense (DoD) Advanced Resear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Linux Kernel
The Linux kernel is a Free and open-source software, free and open source Unix-like kernel (operating system), kernel that is used in many computer systems worldwide. The kernel was created by Linus Torvalds in 1991 and was soon adopted as the kernel for the GNU operating system (OS) which was created to be a free software, free replacement for Unix. Since the late 1990s, it has been included in many Linux distributions, operating system distributions, many of which are called Linux. One such Linux kernel operating system is Android (operating system), Android which is used in many mobile and embedded devices. Most of the kernel code is written in C (programming language), C as supported by the GNU compiler collection (GCC) which has extensions beyond standard C. The code also contains assembly language, assembly code for architecture-specific logic such as optimizing memory use and task execution. The kernel has a Modular programming, modular design such that modules can be inte ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magic SysRq Key
The magic SysRq key is a key combination understood by the Linux kernel, which allows the user to perform various low-level commands regardless of the system's state. It is often used to recover from freeze (computing), freezes, or to booting, reboot a computer without corrupting the filesystem. This key combination provides access to features for disaster recovery. In this sense, it can be considered a form of escape sequence. Principal among the offered commands are means to forcibly unmount file systems, kill processes, recover keyboard state, and write unwritten data to disk. The magic SysRq key cannot work under certain conditions, such as a kernel panic or a hardware failure preventing the kernel from running properly. Implementation The Linux kernel contains sysrq.c, which implements magic SysRq functionality. Magic SysRq functionality is called by serial devices at a low level in the driver code. Commands The key combination consists of and another key, which c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
X Window System
The X Window System (X11, or simply X) is a windowing system for bitmap displays, common on Unix-like operating systems. X originated as part of Project Athena at Massachusetts Institute of Technology (MIT) in 1984. The X protocol has been at version 11 (hence "X11") since September 1987. The X.Org Foundation leads the X project, with the current reference implementation, X.Org Server, available as free and open-source software under the MIT License and similar permissive licenses. Purpose and abilities X is an architecture-independent system for remote graphical user interfaces and input device capabilities. Each person using a networked computer terminal, terminal has the ability to interact with the display with any type of user input device. In its standard distribution it is a complete, albeit simple, display and interface solution which delivers a standard widget toolkit, toolkit and protocol stack for building graphical user interfaces on most Unix-like operating syst ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Login Manager
A login manager is a login system for Unix and Unix-like operating systems. It comprises a login daemon, a login user interface, and a system for tracking login sessions. When a user tries to log in, the login manager passes the user's credentials to an authentication system. Since an X display manager is a graphical user interface for login, some people use the terms ''display manager'' and ''login manager'' synonymously. systemd, an init daemon for Linux, has an integrated login manager; its login daemon is called logind. systemd's login manager is a replacement for the no longer maintained ConsoleKit. See also * BSD Authentication * Name Service Switch * passwd * Pluggable authentication module A pluggable authentication module (PAM) is a mechanism to integrate multiple low-level authentication schemes into a high-level application programming interface (API). PAM allows programs that rely on authentication to be written independently o ... References {{Reflist Comput ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Desktop Environment
In computing, a desktop environment (DE) is an implementation of the desktop metaphor made of a bundle of programs running on top of a computer operating system that share a common graphical user interface (GUI), sometimes described as a graphical shell. The desktop environment was seen mostly on personal computers until the rise of mobile computing. Desktop GUIs help the user to easily access and edit files, while they usually do not provide access to all of the features found in the underlying operating system. Instead, the traditional command-line interface (CLI) is still used when full control over the operating system is required. A desktop environment typically consists of icons, windows, toolbars, directory (file systems), folders, computer wallpaper, wallpapers and Widget engine, desktop widgets (see Elements of graphical user interfaces and WIMP_(computing), WIMP). A GUI might also provide drag and drop functionality and other features that make the desktop metaphor mo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
