Posted on 02/04/2018 1:16:14 PM PST by SunkenCiv
That is called a "one-time pad cipher". If it is truly random, it is also unbreakable. (That is, IMPOSSIBLE to break. Not "difficult", impossible.) However, each page must truly be used ONE TIME ONLY then destroyed. Using a page even twice fatally compromises the pages that were re-used. The Soviets used one-time pads for some of their communications. They also sometimes got lazy and re-used pages. We cracked the messages (or sections of messages) that were encrypted with reused pages. The rest are untouchable.
See Venona Projects at (ha ha ha) Wikipedia.
Queen Elizabeths Secret Service running eery sunday night at 10 on PBS
Yes I knew it had been around a while and used in various films and books as well. I think I heard about it being used in France during the 100 years war as well.... something to add to my list of things to look up again when I get time.
Wow - thanks. I had assumed that the next best thing would be using a different book for each message. Sorta like - buy 2 sets Hardy boys or Easton presses 100 best books and then using a different book for each message. Hadn’t realized that you couldn’t reuse a page a second time.
Cool stuff to read up on as well.
LOL
Buena!
Was just reading about one-time pads. But it seems that the pages were random generators and the entire message was off one page from what I read. I was thinking that as long as the same letter from the same page of a book wasn’t used it would still be enough to generate lots of messages - given a large enough book.
Is your understanding that only one letter per page from the book can be used and then the page has to be tossed or that it’s one message per page?
Now to make is super secret ...
“ebay uresay otay inkdray ouryay ovaltineyay”
Anybody could eventually decipher it but this wasnt a tool for storing intelligence long term like we do today. It was a tool for battlefield communication between command elements. If the enemy wanted to read an intercept or false flag a greek unit during combat then the enemy general would need to know that today we are using 8 sided 1/2” dowels and not the 5 sided 3/4” dowel.
At least she kept her head, and Henry bestowed a palace and riches upon her. I’m sure her soul was saved, probably can’t say the same for the ex.
That is a very good explanation.
THX!
It’s 3 episodes last week was number 1. It may be on the PBS web site for free for a couple of weeks. number two is tonight.
1) That the numbers in the pad be truly random.
2) That no part of the pad ever gets re-used.
(1) above argues against using a dictionary, a Hardy Boys novel, etc. There are patterns in any language, and the appearance of letters (and of patterns of letters) is not random. For example, in English the letters "T H E" frequently appear together in that order; the letters "U I F" seldom appear together in that order. Dice not truly random, although they're pretty close. Radioactive decay, in my understanding, provides a very good source of truly random numbers.
(2) above is what got the Soviets in trouble in the 1940s. They had more messages than cipher pages, and ended up reusing them.
Ok so slightly different then what I’m thinking of, yours points more to generated cipher pages. My thoughts on the books are that you are using multiple pads (pages of the books) at the same time. This would lead to a change in books only when certain limited use characters (q, etc) are used up in the book selected and not the page so to speak. So a multi-pad situation, unless the book for the specific message can be pinpointed.
yours points more to generated cipher pages.
As I recall, alphabetic text is converted to numeric values (ie: letters to ASCII byte values, or some such thing) and then the numbers are encrypted with the random numbers in the pad.
Or my memory could be completely hosed.
Sounds like a highly complicated code. Turn these intelligence guys loose on the code in the Money Pit.
cool that... been a bit since I dealt with daily crypto on ship so I’ll assume we’re close but not on point with each other. Still good info - best to you and yours.
G0 Navy, Beat Army!
USNA ‘89
Maybe I'll dig out my crypto texts and refresh my memory. I have a feeling I'm missing a little something.
daily crypto on ship
One time pads, or algorithmic ciphers? Don't answer if you shouldn't ...
Solving language puzzles has always been something that I marvel at. Some people seem to have almost supernatural abilities in that area where others like me are poor.
I think I can do as well as the average contestant on Jeopardy but would not do well at Wheel of Fortune.
Yet a lot of ancient writings still have the experts stumped. For example some of the older Minoan Linear script has not been deciphered although they have done a bit on it lately.
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