Editing ROT13 (section)

==Usage==

ROT13 is not intended to be used in modern times. At the time of conception in an era of [[Ancient Roman technology]], the encryption scheme was not represented by a [[mathematical structure]]. The [[Key (cryptography)|key]] to decrypt a message requires no more knowledge than the fact that ROT13 is in use. Even if [[secrecy]] does not fail, any alien party or individual, capable of intercepting the message, could break the code by spending enough time on decoding the text through [[Frequency analysis (cryptanalysis)|frequency analysis]]<ref name="schneier" /> or finding other [[String-searching algorithm|patterns]].

In the early 1980s, people used ROT13 in their messages on [[Usenet newsgroup|Usenet newsgroup servers]]<ref name="jargon">{{Cite web |date=29 December 2003 |editor-last=Raymond |editor-first=Eric S. |editor-link=Eric S. Raymond |title=ROT13 |url=http://www.catb.org/~esr/jargon/html/R/rot13.html |url-status=live |archive-url=https://web.archive.org/web/20120113164436/http://www.catb.org/~esr/jargon/html/R/rot13.html |archive-date=13 January 2012 |access-date=19 September 2007 |work=The Jargon File, 4.4.7}}</ref>
They did this to hide potentially offensive jokes, or to obscure an answer to a puzzle or other [[Spoiler (media)|spoiler]],<ref name="netiquette">{{Cite web | url=https://datatracker.ietf.org/doc/html/rfc1855#section-3.1.3 | title=RFC 1855 - Netiquette Guidelines | last=Hambridge | first=Sally | publisher=Internet Engineering Task Force | date=1995-10-01 | access-date=2025-01-02 | archive-url=https://web.archive.org/web/20250102045838/https://datatracker.ietf.org/doc/html/rfc1855#section-3.1.3 | archive-date=2025-01-02 }}</ref> or to fool less sophisticated [[spam bots]]<sup>[''[[Wikipedia:Accuracy dispute#Disputed statement|dubious]] – [[Talk:ROT13#Dubious|discuss]]'']</sup>.
ROT13 has been the subject of many jokes.

The 1989 [[International Obfuscated C Code Contest]] (IOCCC) included an entry by Brian Westley. Westley's [[computer program]] can be encoded in ROT13 or reversed and still [[compiler|compiles]] correctly. Its operation, when executed, is either to perform ROT13 encoding on, or to reverse its input.<ref>{{Cite web |last=Westley |first=Brian |year=1989 |title=westley.c |url=http://www.ioccc.org/1989/westley.c |url-status=live |archive-url=https://web.archive.org/web/20120609004219/http://www.ioccc.org/1989/westley.c |archive-date=9 June 2012 |access-date=13 August 2007 |work=[[IOCCC]]}}</ref>

In December 1999, it was found that [[Netscape Communicator]] used ROT13 as part of an insecure scheme to store email passwords.<ref>{{Cite CiteSeerX |citeseerx=10.1.1.15.9271 |author=Hollebeek, Tim |author2=Viega, John |author-link2=John Viega |title=Bad Cryptography in the Netscape Browser: A Case Study}}</ref> 

In 2001, Russian programmer [[Dimitry Sklyarov]] demonstrated that an eBook vendor, New Paradigm Research Group (NPRG), used ROT13 to encrypt their documents.  It has been speculated that NPRG may have mistaken the ROT13 toy example—provided with the [[Adobe Systems|Adobe]] eBook [[software development kit]]—for a serious encryption scheme.<ref>{{Cite web |last=Perens |first=Bruce |author-link=Bruce Perens |date=1 September 2001 |title=Dimitry Sklyarov: Enemy or friend? |url=https://www.zdnet.com/article/dimitry-sklyarov-enemy-or-friend/ |url-status=live |archive-url=https://web.archive.org/web/20141017174003/http://www.zdnet.com/news/dimitry-sklyarov-enemy-or-friend/116424 |archive-date=17 October 2014 |access-date=3 February 2011 |publisher=[[ZDNet News]]}}</ref> Windows XP uses ROT13 on some of its registry keys.<ref>{{Cite web |date=24 July 2006 |title=ROT13 is used in Windows |url=https://blog.didierstevens.com/2006/07/24/rot13-is-used-in-windows-you%E2%80%99re-joking/ |url-status=live |archive-url=https://web.archive.org/web/20161220182919/https://blog.didierstevens.com/2006/07/24/rot13-is-used-in-windows-you%E2%80%99re-joking/ |archive-date=20 December 2016 |access-date=15 December 2016}}</ref> ROT13 is also used in the [[fortune (Unix)|Unix fortune program]] to conceal potentially offensive [[dicta]].

[[Johann Ernst Elias Bessler]], an 18th-century clock maker and constructor of [[perpetual motion]] machines, pointed out that ROT13 encodes his surname as ''Orffyre''. He used its [[latinisation of names|latinised]] form, ''Orffyreus'', as his pseudonym.<ref>{{cite web|url=https://lockhaven.edu/~dsimanek/museum/people/people.htm|title=Perpetual Futility: A short history of the search for perpetual motion|last=Simanek|first=Donald E.|date=2012|website=The Museum of Unworkable Devices|access-date=28 October 2020|archive-date=10 October 2020|archive-url=https://web.archive.org/web/20201010110525/https://www.lockhaven.edu/~dsimanek/museum/people/people.htm|url-status=live}}</ref>