A
virtual keyboard is a software and/or hardware component that allows a user to enter characters. A virtual keyboard can usually be operated with multiple input devices, which may include an actual keyboard, a computer mouse, a headmouse, and an eyemouse.
On a desktop PC, one purpose of a virtual keyboard is to provide an alternative input mechanism for users with disabilities who cannot use a physical keyboard. Another major use for an on-screen keyboard is for bi- or multi-lingual users, who continually need to switch between different character sets and/or alphabets. Although hardware keyboards are available with dual layouts (for example Cyrillic/Latin letters in various national layouts), the on-screen keyboard provides a handy substitute while working at different stations or on laptops, which seldom come with dual layouts.
The standard on-screen keyboard utility on most Windows systems allows hot-key switching between layouts from the physical keyboard (typically alt-shift but this is user configurable), simultaneously changing both the hardware and the software keyboard layout. In addition, a symbol in the sys-tray alerts the user to the currently active layout. Although Linux supports this fast manual keyboard-layout switching function, most popular Linux on-screen keyboards such as gtkeyboard, Matchbox-keyboard or Kvkbd do not react correctly. Kvkbd for example defines its visible layout according to the first defined layout in Keyboard Preferences rather than the default layout, causing the application to output incorrect characters if the first layout on the list is not the default. Activating a hot-key layout switch will cause the application to change its output according to another keyboard layout, but the visible on-screen layout doesn't change, leaving the user blind as to which keyboard layout he is using. Until these deficiencies are corrected, Linux on-screen keyboards remain of limited usefulness for multi-lingual / multi-alphabet users.
On devices which lack a physical keyboard (such as
personal digital assistantA personal digital assistant is a handheld computer, also known as a palmtop computer. Newer PDAs commonly have color screens and audio capabilities, enabling them to be used as mobile phones , web browsers, or portable media players. Many PDAs can access the Internet, intranets or extranets...
s or
touchscreenA touchscreen is a display that can detect the presence and location of a touch within the display area. The term generally refers to touch or contact to the display of the device by a finger or hand. Touchscreens can also sense other passive objects, such as a stylus. However, if the object...
equipped cell phones), it is common for the user to input text by tapping a virtual keyboard built into the
operating systemAn operating system is an interface between hardware and user which is responsible for the management and coordination of activities and the sharing of the resources of the computer that acts as a host for computing applications run on the machine. As a host, one of the purposes of an operating...
of the device. Virtual keyboards are also used as features of
emulation softwareA virtual machine is a software implementation of a machine that executes programs like a physical machine.-Definitions:...
for systems that have fewer buttons than a computer keyboard would have.
Virtual keyboards can be categorized by the following aspects:
- physical keyboards with distinct keys comprising electronically changeable displays integrated in the keypads
- virtual keyboards with touchscreen keyboard layouts or sensing areas
- optically projected keyboard
A projection keyboard is a virtual keyboard that can be projected and touched on any surface. The keyboard watches finger movements and translates them into keystrokes in the device. Most systems can also function as a virtual mouse or even as a virtual piano...
layouts or similar arrangements of "keys" or sensing areas
- optically detected human hand and finger motions
- virtual keyboards to allow input from a variety of input devices, such as a computer mouse
In computing, a mouse is a pointing device that functions by detecting two-dimensional motion relative to its supporting surface. Physically, a mouse consists of an object held under one of the user's hands, with one or more buttons...
, switchMany people with severe physical or cognitive impairment use one or more switches to access computers. A switch is an assistive technology device that replaces the need to use a computer keyboard or a mouse.-Types of switch:...
or other assistive technologyAssistive technology is a generic term that includes assistive, adaptive, and rehabilitative devices for people with disabilities and includes the process used in selecting, locating, and using them....
device.
An optical virtual keyboard has been invented and patented by
IBMInternational Business Machines Corporation, abbreviated IBM, is a multinational computer technology and IT consulting corporation headquartered in Armonk, Town of North Castle, New York, United States. The company is one of the few information technology companies with a continuous history dating...
engineers in 2008. It optically detects and analyses human hand and finger motions and interprets them as operations on a physically non-existent input device like a surface having painted keys. In that way it allows to emulate unlimited types of manually operated input devices such as a mouse or keyboard. All mechanical input units can be replaced by such virtual devices, optimized for the current application and for the user's physiology maintaining speed, simplicity and unambiguity of manual data input.
On the Internet, various JavaScript virtual keyboards have been created, allowing users to type their own languages on foreign keyboards, particularly in Internet cafes.
Security considerations
Virtual keyboards may be used in some cases to reduce the risk of
keystroke loggingKeystroke logging is the practice of noting the keys struck on a keyboard, typically in a covert manner so that the person using the keyboard is unaware that their actions are being monitored...
. For example,
WestpacWestpac , is a multinational Financial services company and became the largest bank in Australia after it took over St George., and, the second-largest bank in New Zealand...
’s
online banking service uses a virtual keyboard for the password entry, as does
TreasuryDirectTreasuryDirect is a website run by the United States Treasury that allows US individual investors to purchase Treasury securities such as T-Bills and others directly from the U.S. government...
(see picture). It is more difficult for malware to monitor the display and mouse to obtain the data entered via the virtual keyboard, than it is to monitor real keystrokes. However it is possible, for example by recording screenshots at regular intervals or upon each mouse click.
The use of an on-screen keyboard on which the user "types" with mouse clicks can increase the risk of password disclosure by
shoulder surfingIn computer security, shoulder surfing refers to using direct observation techniques, such as looking over someone's shoulder, to get information...
, because:
- An observer can typically watch the screen more easily (and less suspiciously) than the keyboard, and see which characters the mouse moves to.
- Some implementations of the on-screen keyboard may give visual feedback of the "key" clicked, eg by changing its colour briefly. This makes it much easier for an observer to read the data from the screen. In the worst case, the implementation may leave the focus
In computing, the focus indicates the component of the graphical user interface which is currently selected to receive input. Text entered at the keyboard or pasted from a clipboard is sent to the component which currently has the focus. Moving the focus away from a specific user interface element...
on the most recently clicked "key" until the next virtual key is clicked, thus allowing the observer time to read each character even after the mouse starts moving to the next character.
- A user may not be able to "point and click" as fast as they could type on a keyboard, thus making it easier for the observer.
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