„Klopfcode“ – Versionsunterschied
| [ungesichtete Version] | [ungesichtete Version] |
Inhalt gelöscht Inhalt hinzugefügt
K Reverted edits by 84.13.159.20 (talk) to last revision by ClueBot NG (HG) |
|||
Zeile 26:
== Design ==
The tap code is based on a [[Polybius square]], a 5×5 grid of letters representing all the letters of the [[Latin alphabet]], except for K, which is represented by C. Each letter is communicated by tapping two numbers: the first designating the row (horizontally) and the second designating the column (vertically). The letter "X" is used to break up sentences. The tap code requires the listener to only discriminate the timing of the taps to isolate letters. For example, to specify the letter "A", one taps once, pauses, and then taps once again.
Or to communicate the word "water", the cipher would be the following (the pause between each number in a pair is smaller than the pause between one pair and the next):
{| class="wikitable"
|-
! W !! A !! T !! E !! R
|-
| <p align="center">5, 2</p> || <p align="center">1, 1</p> || <p align="center">4, 4</p> || <p align="center">1, 5</p> || <p align="center">4, 2</p>
|-
| <p align="center">····· ··</p> || <p align="center">· ·</p> || <p align="center">···· ····</p> || <p align="center">· ·····</p> || <p align="center">···· ··</p>
|}
Because of the difficulty and length of time required for specifying a single letter, prisoners often devise [[abbreviations]] and [[acronyms]] for common items or phrases, such as "GN" for ''Good night'', or "GBU" for ''God bless you.''<ref name="pbs"/>
By comparison, [[Morse code]] is harder to send by tapping or banging because it requires the ability to create two differently sounding taps (representing the ''dits'' and ''dahs'' of Morse code). A Morse code novice would also need to keep a "cheat sheet" until he or she remembers every letter's code, which the captors would likely confiscate. Tap code can be more easily decoded in one's head by mentally using the table.
== History ==
The origins of this encoding go back to the [[Polybius square]] of [[Ancient Greece]]. As the "knock code", a [[Cyrillic script]] version is said to have been used by [[nihilist movement|nihilist]] prisoners of the [[Russia]]n [[Czar]]s.<ref>[[David Kahn (writer)|David Kahn]], ''The Codebreakers - The Story of Secret Writing''. 1967. ISBN 978-0-684-83130-5.</ref> The knock code is featured in [[Arthur Koestler]]'s classic 1941 work ''[[Darkness at Noon]]''.<ref>Koestler, Arthur, ''Darkness at Noon'' (1941). Translated by Daphne Hardy. See page 19 of the Bantam Publishing paperback, 1981 printing for more info.</ref>
[[United States]] [[prisoners of war]] during the [[Vietnam War]] are most known for having used the tap code. It was introduced in June 1965 by four POWs held in the [[Hanoi Hilton|Hoa Lo "Hanoi Hilton" prison]]: Captain Carlyle "Smitty" Harris, Lieutenant Phillip Butler, Lieutenant Robert Peel, and Lieutenant Commander Robert Shumaker.<ref name="pbs">{{cite web | url=http://www.pbs.org/wgbh/amex/honor/sfeature/sf_tap.html | title=''Return with Honor'': The Tap Code | work=[[American Experience]] | publisher=[[Public Broadcasting Service|PBS]] | year=1999 | accessdate=2008-04-08}}</ref> Smitty Harris had heard of the tap code being used by prisoners in [[World War II]]<ref name="au">{{cite news | url=http://www.au.af.mil/au/awc/awcgate/awc-pow.htm | title=Vets, Flyers discuss ideology, time in POW camps | author=Staff Sgt. Jason Tudor | publisher=[[Air Force News Service]] | date=1998-03-18 | accessdate=2008-04-08}}</ref> and remembered a [[United States Air Force]] instructor who had discussed it as well.<ref name="pbs"/>
In Vietnam, the tap code became a very successful way for otherwise isolated prisoners to communicate.<ref name="au"/> POWs would use the tap code in order to communicate to each other between cells in a way which the guards would be unable to pick up on. They used it to communicate everything from what questions [[interrogation|interrogators]] were asking (in order for everyone to stay consistent with a deceptive or bogus story), to who was hurt and needed others to donate meager food rations. It was easy to teach and newly arrived prisoners became fluent in it within a few days.<ref>{{cite book | last=McCain | first=John | authorlink=John McCain | coauthors=[[Mark Salter]] | title=''[[Faith of My Fathers]]'' | publisher=[[Random House]] | year=1999 | isbn=0-375-50191-6}} pp. 211–212.</ref><ref name="brace"/> It was even used when prisoners were sitting next to each other but not allowed to talk, by tapping on anothers' thigh.<ref name="brace">{{cite book | last=Brace |first=Ernest C. |authorlink=Ernest C. Brace | title=A Code to Keep: The true story of America's longest held civilian prisoner of war in Vietnam | publisher=[[St. Martin's Press]] | year=1988 | isbn=0-7090-3560-8}} pp. 171–172, 187–188.</ref> By overcoming isolation with the tap code, prisoners were able to maintain a [[chain of command]] and keep up [[morale]].<ref name="au"/>
==References==
| |||