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norwegian
Premium
join:2005-02-15
Outback
reply to Link Logger

Re: Can anyone crack pigeon's wartime code?


So I gather using a random cipher stops the patterns of the English language from forming?

Such as 'E' is the most common letter.
'Q' has to have a 'U' follow it, etc.
Little subtleties like that to give away the form of the message?

Mind you when back at school I could have really dug this, I hate letting anything beat me. I started to try to split sections but if the key used has no set pattern, or void of a rhythm; I can't see an easy answer, which I guess as MIXZ1 See Profile points out becomes a "cannot be broken" category.

Still a very interesting story - I wonder what people, for example E. Kaspersky would be thinking in a read of this article.
--
The only thing necessary for the triumph of evil is for good men to do nothing - Edmund Burke



Blackbird
Built for Speed
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join:2005-01-14
Fort Wayne, IN
kudos:3
Reviews:
·Frontier Communi..

1 edit
said by norwegian:

So I gather using a random cipher stops the patterns of the English language from forming?

Such as 'E' is the most common letter.
'Q' has to have a 'U' follow it, etc.
Little subtleties like that to give away the form of the message? ...

Think of it as representing each plaintext message letter by a number (for its alphabet position), then add a random digit to it (a digit copied from the corresponding position in the key string). Their sum would represent the alphabetic positional value of the coded letter to be sent. eg: a plaintext "b" (=2) in the first character position of the message would get added to, say, an "e" (=5) or even the actual digit "5" in the first character position of the key string... the sum is 7, which corresponds in the alphabet to "g" which is what gets sent. If the sum exceeds 26 (the max number of letters in the alphabet, the count simply starts over so that a 29 corresponds to a 3 (or a "c"). The recipient simply reverses the process, subtracting his identical key's character value for the first key string position from the value of the sent-message first-character position to recover the correct plaintext message value.

By using truly random key strings from the one-time pad, the message sent is randomized beyond unwanted recovery, provided that the key is only ever used once and that the message is kept short enough. To assure shortness, the key page is limited in length. Each message sent uses a different one-time pad, so a recoverable pattern never emerges. The "pad" term derives from the original practice of providing key strings (one to a page) in a pad of pages, tearing off, using and then destroying them one at a time as messages are sent.

One time pads are a pain to use unless employing computers/machines to assist - but those create undesirable trails, so one-times are usually reserved for very critical or crisis messaging.
--
“The American Republic will endure until the day Congress discovers that it can bribe the public with the public's money.” A. de Tocqueville

MIXZ1

join:2001-01-02
Mexico
Reviews:
·Prodigy Infinitum
reply to norwegian
said by norwegian:

So I gather using a random cipher stops the patterns of the English language from forming?

I repeat, when used correctly an OTP message is unbreakable without the OTP. Simple newspaper puzzle and jumble rules don't apply. And a point to remember is that these messages were often coded under duress, sometimes in terrible conditions, without the use of any computational devices other than a paper and pen. Not even the million monkeys can decode this one.


StuartMW
Who Is John Galt?
Premium
join:2000-08-06
Galt's Gulch
kudos:3
said by MIXZ1:

Not even the million monkeys can decode this one.

Well an infinite number of monkeys given an infinite amount of time might. You might also get the complete works of William Shakespeare.

That said I don't see the point. Even if decrypted a 70+ year old message would most likely be completely meaningless to anyone living now.
--
Don't feed trolls--it only makes them grow!


Blackbird
Built for Speed
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Fort Wayne, IN
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said by StuartMW:

... I don't see the point. Even if decrypted a 70+ year old message would most likely be completely meaningless to anyone living now.

It's the challenge involved in it. And who knows, maybe it involved a salacious revelation about a hitherto-unknown Hitler mistress... or an urgent request for another case of His Majesty's finest malt to be sent to the front. Inquiring minds want to know, as do folks with entirely too much time on their hands...
--
“The American Republic will endure until the day Congress discovers that it can bribe the public with the public's money.” A. de Tocqueville