In
computer security
Computer security, cybersecurity (cyber security), or information technology security (IT security) is the protection of computer systems and networks from attack by malicious actors that may result in unauthorized information disclosure, t ...
, logging in (or logging on, signing in, or signing on) is the process by which an individual gains
access
Access may refer to:
Companies and organizations
* ACCESS (Australia), an Australian youth network
* Access (credit card), a former credit card in the United Kingdom
* Access Co., a Japanese software company
* Access Healthcare, an Indian BPO se ...
to a
computer system
A computer is a machine that can be programmed to carry out sequences of arithmetic or logical operations ( computation) automatically. Modern digital electronic computers can perform generic sets of operations known as programs. These prog ...
by
identifying and
authenticating themselves. The
user credentials are typically some form of
username
A user is a person who utilizes a computer or network service.
A user often has a user account and is identified to the system by a username (or user name). Other terms for username include login name, screenname (or screen name), accoun ...
and a matching
password
A password, sometimes called a passcode (for example in Apple devices), is secret data, typically a string of characters, usually used to confirm a user's identity. Traditionally, passwords were expected to be memorized, but the large number of ...
,
and these credentials themselves are sometimes referred to as ''a'' login (or logon, sign-in, sign-on).
[Oxford Dictionaries](_blank)
definition of ''login''.
detail and definition of ''login'' and ''logging in''. In practice, modern secure systems often require a
second factor such as
email
Electronic mail (email or e-mail) is a method of exchanging messages ("mail") between people using electronic devices. Email was thus conceived as the electronic ( digital) version of, or counterpart to, mail, at a time when "mail" mean ...
or
SMS confirmation for extra security.
Social login
Social login is a form of single sign-on using existing information from a social networking service such as Facebook, Twitter or Google, to sign into a third party website instead of creating a new login account specifically for that website. It ...
allows a user to use existing user credentials from a
social networking service to sign in to or create an account on a new website.
When access is no longer needed, the user can log out (log off, sign out or sign off).
Procedure
![Fingerprint scanner identification](https://upload.wikimedia.org/wikipedia/commons/6/67/Fingerprint_scanner_identification.jpg)
Logging in is usually used to enter a specific page, website or application, which trespassers cannot see. Once the user is logged in, the login token may be used to track what actions the user has taken while connected to the site. Logging out may be performed explicitly by the
user taking some actions, such as entering the appropriate
command
Command may refer to:
Computing
* Command (computing), a statement in a computer language
* COMMAND.COM, the default operating system shell and command-line interpreter for DOS
* Command key, a modifier key on Apple Macintosh computer keyboards
* ...
or clicking a
website
A website (also written as a web site) is a collection of web pages and related content that is identified by a common domain name and published on at least one web server. Examples of notable websites are Google, Facebook, Amazon, and Wi ...
link label as such. It can also be done implicitly, such as by the user powering off his or her workstation, closing a
web browser
A web browser is application software for accessing websites. When a user requests a web page from a particular website, the browser retrieves its files from a web server and then displays the page on the user's screen. Browsers are used o ...
window, leaving a website, or not refreshing a website within a defined period.
A login page may have a return URL parameter, which specifies where to redirect back after logging in or out. For example, it is
returnto=
on this site.
In the case of websites that use
cookies
A cookie is a baked or cooked snack or dessert that is typically small, flat and sweet. It usually contains flour, sugar, egg, and some type of oil, fat, or butter. It may include other ingredients such as raisins, oats, chocolate chi ...
to track sessions, when the user logs out, session-only cookies from that site will usually be deleted from the user's computer. In addition, the server invalidates any associations with the session, thereby making any session-handle in the user's cookie store useless. This feature comes in handy if the user is using a
public computer
A public computer (or public access computer) is any of various computers available in public areas. Some places where public computers may be available are libraries, schools, or dedicated facilities run by government.
Public computers share simi ...
or a computer that is using a
public wireless connection. As a security precaution, one should not rely on implicit means of logging out of a system, especially not on a public computer; instead, one should explicitly log out and wait for the confirmation that this request has taken place.
Logging out of a computer, when leaving it, is a common security practice preventing unauthorised users from tampering with it. There are also people who choose to have a password-protected
screensaver
A screensaver (or screen saver) is a computer program that blanks the display screen or fills it with moving images or patterns when the computer has been idle for a designated time. The original purpose of screensavers was to prevent phosphor ...
set to activate after some period of inactivity, thereby requiring the user to re-enter his or her login credentials to unlock the screensaver and gain access to the system. There can be different methods of logging in that may be via image, fingerprints,
eye scan, password (oral or textual input), etc.
History and etymology
![IBM AIX 4 Login Prompt](https://upload.wikimedia.org/wikipedia/commons/f/f0/IBM_AIX_4_Login_Prompt.jpeg)
The terms became common with the
time sharing
In computing, time-sharing is the sharing of a computing resource among many users at the same time by means of multiprogramming and multi-tasking.DEC Timesharing (1965), by Peter Clark, The DEC Professional, Volume 1, Number 1
Its emergence ...
systems of the 1960s and
Bulletin Board Systems (BBS) in the 1970s. Early
home computers and
personal computer
A personal computer (PC) is a multi-purpose microcomputer whose size, capabilities, and price make it feasible for individual use. Personal computers are intended to be operated directly by an end user, rather than by a computer expert or tec ...
s did not generally require them until
Windows NT
Windows NT is a proprietary graphical operating system produced by Microsoft, the first version of which was released on July 27, 1993. It is a processor-independent, multiprocessing and multi-user operating system.
The first version of Win ...
,
OS/2
OS/2 (Operating System/2) is a series of computer operating systems, initially created by Microsoft and IBM under the leadership of IBM software designer Ed Iacobucci. As a result of a feud between the two companies over how to position OS/2 r ...
and
Linux
Linux ( or ) is a family of open-source Unix-like operating systems based on the Linux kernel, an operating system kernel first released on September 17, 1991, by Linus Torvalds. Linux is typically packaged as a Linux distribution, w ...
in the 1990s.
The noun ''login'' comes from the verb ''(to) log in'' and by analogy with the verb ''to clock in''. Computer systems keep a ''
log
Log most often refers to:
* Trunk (botany), the stem and main wooden axis of a tree, called logs when cut
** Logging, cutting down trees for logs
** Firewood, logs used for fuel
** Lumber or timber, converted from wood logs
* Logarithm, in mathe ...
'' of users' access to the system. The term "log" comes from the
chip log
A chip log, also called common log, ship log, or just log, is a navigation tool mariners use to estimate the speed of a vessel through water. The word ''knot'', to mean nautical mile per hour, derives from this measurement method.
History
All ...
historically used to record distance travelled at sea and was recorded in a
ship's log
A logbook (a ship's logs or simply log) is a record of important events in the management, operation, and navigation of a ship. It is essential to traditional navigation, and must be filled in at least daily.
The term originally referred to a bo ...
or
log book. To ''sign in'' connotes the same idea, but it's based on the analogy of manually signing a log book or
visitors book.
While there is no agreed difference in meaning between the three terms (''login'', ''logon'' and ''sign''-''in''), different technical communities tend to prefer one over another – Unix, Novell, Linux and Apple typically use ''login'', and Apple's
style guide says ''"Users log in to a file server (not log on to)...".'' By contrast, Microsoft's style guides traditionally suggested the opposite and prescribed ''log on'' and ''logon''.
[ In the past, Microsoft reserved ''sign-in'' to when accessing the Internet,]["Use log on or log on to... Do not use log in, login", 2004, ''Manual of Style for Technical Publications'', 3rd edition, p. 295, Microsoft.com.] but from Windows 8
Windows 8 is a major release of the Windows NT operating system developed by Microsoft. It was released to manufacturing on August 1, 2012; it was subsequently made available for download via MSDN and TechNet on August 15, 2012, and later to ...
onward it has moved to the ''sign-in'' terminology for local authentication."Sign in to or out of Windows"
Microsoft.com.
See also
*
Computer security
Computer security, cybersecurity (cyber security), or information technology security (IT security) is the protection of computer systems and networks from attack by malicious actors that may result in unauthorized information disclosure, t ...
*
Login session
In computing, a login session is the period of activity between a user logging in and logging out of a (multi-user) system.
On Unix and Unix-like operating systems, a login session takes one of two main forms:
* When a textual user interface i ...
*
Login spoofing
Login spoofings are techniques used to steal a user's password. The user is presented with an ordinary looking login prompt for username and password, which is actually a malicious program (usually called a Trojan horse) under the control of the ...
*
OpenID
OpenID is an open standard and decentralized authentication protocol promoted by the non-profit OpenID Foundation. It allows users to be authenticated by co-operating sites (known as relying parties, or RP) using a third-party identity provider ...
*
Password
A password, sometimes called a passcode (for example in Apple devices), is secret data, typically a string of characters, usually used to confirm a user's identity. Traditionally, passwords were expected to be memorized, but the large number of ...
*
Password policy
A password policy is a set of rules designed to enhance computer security by encouraging users to employ strong passwords and use them properly. A password policy is often part of an organization's official regulations and may be taught as part o ...
*
Personal identification number
*
/var/log/wtmp
References
{{Authority control
Authentication methods
User interfaces
Computer access control