Editing Password (section)

==History==
Passwords have been used since ancient times. Sentries would challenge those wishing to enter an area to supply a password or ''watchword'', and would only allow a person or group to pass if they knew the password. [[Polybius]] describes the system for the distribution of watchwords in the [[Military of ancient Rome|Roman military]] as follows:

<blockquote>The way in which they secure the passing round of the watchword for the night is as follows: from the tenth [[maniple (military unit)|maniple]] of each class of infantry and cavalry, the maniple which is encamped at the lower end of the street, a man is chosen who is relieved from guard duty, and he attends every day at sunset at the tent of the [[tribune]], and receiving from him the watchword—that is a wooden tablet with the word inscribed on it – takes his leave, and on returning to his quarters passes on the watchword and tablet before witnesses to the commander of the next maniple, who in turn passes it to the one next to him. All do the same until it reaches the first maniples, those encamped near the tents of the tribunes. These latter are obliged to deliver the tablet to the tribunes before dark. So that if all those issued are returned, the tribune knows that the watchword has been given to all the maniples, and has passed through all on its way back to him. If any one of them is missing, he makes inquiry at once, as he knows by the marks from what quarter the tablet has not returned, and whoever is responsible for the stoppage meets with the punishment he merits.<ref>[http://ancienthistory.about.com/library/bl/bl_text_polybius6.htm Polybius on the Roman Military] {{webarchive|url=https://web.archive.org/web/20080207011711/http://ancienthistory.about.com/library/bl/bl_text_polybius6.htm |date=2008-02-07 }}. Ancienthistory.about.com (2012-04-13). Retrieved on 2012-05-20.</ref></blockquote>

Passwords in military use evolved to include not just a password, but a password and a counterpassword; for example in the opening days of the [[Invasion of Normandy|Battle of Normandy]], paratroopers of the U.S. 101st Airborne Division used a password—''flash''—which was presented as a challenge, and answered with the correct response—''thunder''. The challenge and response were changed every three days. American paratroopers also famously used a device known as a "cricket" on [[D-Day]] in place of a password system as a temporarily unique method of identification; one metallic click given by the device in lieu of a password was to be met by two clicks in reply.<ref>{{cite book|author=Mark Bando|title=101st Airborne: The Screaming Eagles in World War II|url=https://books.google.com/books?id=cBSBtgAACAAJ|access-date=20 May 2012|year=2007|publisher=Mbi Publishing Company|isbn=978-0-7603-2984-9|url-status=live|archive-url=https://web.archive.org/web/20130602083437/http://books.google.com/books?id=cBSBtgAACAAJ|archive-date=2 June 2013}}</ref>

Passwords have been used with computers since the earliest days of computing. The [[Compatible Time-Sharing System]] (CTSS), an operating system introduced at [[MIT]] in 1961, was the first computer system to implement password login.<ref>{{cite magazine |last1=McMillan |first1=Robert |title=The World's First Computer Password? It Was Useless Too |url=https://www.wired.com/2012/01/computer-password/ |magazine=[[Wired magazine]] |access-date=22 March 2019 |date=27 January 2012}}</ref><ref>{{cite web |last1=Hunt |first1=Troy |title=Passwords Evolved: Authentication Guidance for the Modern Era |url=https://www.troyhunt.com/passwords-evolved-authentication-guidance-for-the-modern-era/ |access-date=22 March 2019 |date=26 July 2017}}</ref> CTSS had a LOGIN command that requested a user password. "After typing PASSWORD, the system turns off the printing mechanism, if possible, so that the user may type in his password with privacy."<ref>CTSS Programmers Guide, 2nd Ed., MIT Press, 1965</ref> In the early 1970s, [[Robert Morris (cryptographer)|Robert Morris]] developed a system of storing login passwords in a hashed form as part of the [[Unix]] operating system. The system was based on a simulated Hagelin rotor crypto machine, and first appeared in 6th Edition Unix in 1974. A later version of his algorithm, known as [[crypt (Unix)|crypt(3)]], used a 12-bit [[salt (cryptography)|salt]] and invoked a modified form of the [[Data Encryption Standard|DES]] algorithm 25 times to reduce the risk of pre-computed [[dictionary attack]]s.<ref>{{cite journal |title=Password Security: A Case History. |journal=Bell Laboratories |author1=Morris, Robert |author2=Thompson, Ken |date=3 April 1978 |citeseerx=10.1.1.128.1635}}</ref>

In modern times, [[user (computing)|user names]] and passwords are commonly used by people during a [[logging (computer security)|log in]] process that [[access control|controls access]] to protected computer [[operating system]]s, [[mobile phone]]s, [[cable TV]] decoders, [[automated teller machine]]s (ATMs), etc. A typical [[computer user]] has passwords for multiple purposes: logging into accounts, retrieving [[e-mail]], accessing applications, databases, networks, web sites, and even reading the morning newspaper online.