Re: A diagonal shift?
AK Wilks: Questions:
1. You mentioned the analysis by FBI CRR (Code) Unit Chief Olson. He thought the 340 might be divided into two parts with the second part starting IIRC at line 11. You said in your study IIRC lines 1-3 & 11-13 stood out as different. Could that be consistent with those lines being the start of a new message and a new coding scheme?
2. You mentioned lines 6-15 as showing least amount of directional bias? Would you tend to think a word search type message with possible diagonal and/or vertical words would be more likely to occur in lines 6-15?
Or roughly:
1-10 Mostly or all horizontal
11-16 Possible some or mostly diagonal
14-20 Possible some or mostly vertical?
Thanks.
Yes I agree the lack of directional bias, shown in Prof Knight's work and your work at least opens the reasonable possibility that parts of the message could be in a word search format with vertical and/or diagonal words and phrases. Worth exploring anyway. And I assume you agree with me, doranchak, glurk and most of the others here that IF there are any vertical or diagonal words we are looking for mostly correct spelling, as is, continuous and absolutely no wide anagrams and preferably no anagrams at all. As I mentioned parts of the Raw Graysmith as reconstructed by Ed, Claston and others show in that 6-15 midrange correct spelling no anagram diagonal words like BOMBS and LIST and towards the bottom in that 14 - 20 range, vertical correct spelling no anagrams vertical words like DUEL, BARS, LEASH, TAKE & LOSE.
1. You mentioned the analysis by FBI CRR (Code) Unit Chief Olson. He thought the 340 might be divided into two parts with the second part starting IIRC at line 11. You said in your study IIRC lines 1-3 & 11-13 stood out as different. Could that be consistent with those lines being the start of a new message and a new coding scheme?
2. You mentioned lines 6-15 as showing least amount of directional bias? Would you tend to think a word search type message with possible diagonal and/or vertical words would be more likely to occur in lines 6-15?
Or roughly:
1-10 Mostly or all horizontal
11-16 Possible some or mostly diagonal
14-20 Possible some or mostly vertical?
Jarlve wrote:AK Wilks, thank you for your interest.
It is very hard to answer such questions but I will try to do so and explain my reasoning behind it.
1) No. In the 340 you have 9 rows (1,2,3,7,11,12,13,15,20) that have no repeats. Rows (1,2,3,11,12,13) seem consistent with what is expected for rows that have no repeats. In a 63 symbol cipher it is very normal to have a large amount of rows that have no repeats. And these rows could appear anywhere. The rather small observed difference, I think, was just from comparing rows with no repeats to rows with repeats. A straightforward two part message, 170 characters each, with for instance 2 different encodings is out of the question here. I have done testing and such schemes upset the positional and bigram data of the cipher to a very large degree. There is however a "significant enough" difference between the positional data of the 340 and other CHS ciphers including the 408 which indicates that something else is going on. Likely information travelling up and down somehow when it should have travelled horizontally and/or symbols not being part of the encoding.
When symbols are not part of the encoding a few things happen, they disturb the homophonic cycle and cause a shift of information against what is normally expected. They also cause, in case with a fixed column count of 17 a vertical stretch of information. Which can explain the difference in the positional data by inflation of irregularities.
It is possible that a 2 part message/encoding was "masked" by mixing it more evenly between the rows. For instance, message 1 from rows 1 to 5 and 11 to 15 and message 2 from row 6 to 10 and 16 to 20. But that would still have resulted in a very significant reduction in bigram counts which is not present for the 340. Which is in general another very strong objection versus a 2 part message.
2) Can't say yet. The next step for me is to make a word search and encode it in a few different ways and see how well the bigram counts correlate with what is actually there. Also the bigram test that I did was not well suited to the typical word search, because I wasn't testing for that specifically. And the relevance of a bigram test on a 170 character string can also be questioned. I need to remain skeptical, but I also need to do something in order to make progress.
At the moment the word search looks like a promising direction for which I will do more work.
Thanks.
Yes I agree the lack of directional bias, shown in Prof Knight's work and your work at least opens the reasonable possibility that parts of the message could be in a word search format with vertical and/or diagonal words and phrases. Worth exploring anyway. And I assume you agree with me, doranchak, glurk and most of the others here that IF there are any vertical or diagonal words we are looking for mostly correct spelling, as is, continuous and absolutely no wide anagrams and preferably no anagrams at all. As I mentioned parts of the Raw Graysmith as reconstructed by Ed, Claston and others show in that 6-15 midrange correct spelling no anagram diagonal words like BOMBS and LIST and towards the bottom in that 14 - 20 range, vertical correct spelling no anagrams vertical words like DUEL, BARS, LEASH, TAKE & LOSE.

