Caustic Logic
Illuminator
- Joined
- Apr 24, 2007
- Messages
- 4,494
Note to mods: Technically this might fit better in a science forum, or history, or something, but it does tie in with the PH conspiracy angle, so I’m posting it here.
Hey, I'm back after a long break. Thank you, thank you all. I’ve been looking more in-depth into the Pearl Harbor attack (yes, the "FDR knew" angle), and at the moment I’m trying to sort out the issue of the Japanese naval code dubbed JN-25B. The main story of this code for the war is the secret window onto Japanese navy plans that was finally broken in early ’42, giving us a surprise win at Midway and Yamamoto’s head, but the crack came too late to see the Pearl Harbor attack coming. I’d like to offer a mix of observations and questions for some of the more learned here.
I understand that as used, it was a code using tens of thousands of 5-digit sequences to represent Japanese Kana, and further superencyphered with a book of random-number ‘additives’ that was changed at intervals. In essence, it seems, the encryption must be neutralized, at least in part, to even see the code, which then had to be analyzed for patterns to narrow down to the possible meanings of the number strings.
The original JN-25 was instituted 1939, which U.S. cryptanalysts had made some progress on before it was replaced by the JN-25B version, essentially a new code, on Dec 1 1940
Q1) minor question - why was it not called JN-26? Is it a different code altogether, or a variant of the first? Did the change invalidate the previous progress?
As it appears so far, subsequent changes that frustrated cracking efforts were not with the code itself, but with the encrypting additive books. This occurred at intervals – once in early 1941, again on June1, again on August 1, and again on Dec 4, just before the surprise attack. If I understand right, the code-breaking progress until then is still valid and ready to proceed once the cipher is cracked anew.
Q2) Is this correct, or did the additive changes alter the underlying code, invalidating previous work?
Evidence it was not broken by US cryptographers appears pretty strong: Budiansky claims to have found multiple primary sources detailing the actual progress on the code and its ciphers, indicating that no JN-25 transmissions were read as current intelligence prior to Dec 7. This may be an oversimplification (eg; there may have been particles of useful intel, rather than none, so far as I know), but it seems to me essentially correct.
Contradictory evidence is weak; Robert Stinnett – whose work seems to be full of flaws I’m beginning to latch onto - claims the US had broken the code entirely by mid-November 1941 at latest. His main evidence for this is a letter he found that seems to say something else entirely – something closer to “we’re trying hard to break the code.” http://www.nybooks.com/articles/14086
So it appears the US, at least in the known channels of analysis (Hypo, Cast, etc.) did not get more than a smidgen of the code readable – but there were people other than the US working it, especially the British and the Dutch. James Rusbridger and Eric Nave claim the British broke the code and were able to read JN-25 messages at will well before 12/7. The whole thing sounds fishy but I haven’t looked close yet.
Q3) Can anyone debunk the British JN-25 decode prior to 12/7 proposal before I do and save me work?
It may mean nothing, but the 1946 Congressional joint committee's report made no mention of JN-25, or any Japanese coding system. Decodes of intercepts were possible by then, but not called on as evidence – the Japanese plans were instead assembled from memories of their military survivors, and some stray copies that escaped destruction. Adm. Layton found in the 1980s the National Security Archive had “no JN-25 traffic that was actually decrypted before war broke,” “not one single original decrypt made at the time of any JN-25 message” and even looking at later decodes “we evidently did not pick up Yamamoto’s 25 November sailing message” at all. Layton also found British official sources equally non-forthcoming on 1941-era JN-25 decodes. [See “And I was There” available for reading online – pages 206-207, 231-32, 534]
Q4) Am I reading Layton right, that this very important order is not in the archive as received?
Q5) Does anyone have any newer information on where a pre-Dec 7 intercept can be seen so we can see what a “10-15%” readable message looks like?
I have other questions and thoughts for later, but this should generate enough answers to keep me busy for a while.
Hey, I'm back after a long break. Thank you, thank you all. I’ve been looking more in-depth into the Pearl Harbor attack (yes, the "FDR knew" angle), and at the moment I’m trying to sort out the issue of the Japanese naval code dubbed JN-25B. The main story of this code for the war is the secret window onto Japanese navy plans that was finally broken in early ’42, giving us a surprise win at Midway and Yamamoto’s head, but the crack came too late to see the Pearl Harbor attack coming. I’d like to offer a mix of observations and questions for some of the more learned here.
I understand that as used, it was a code using tens of thousands of 5-digit sequences to represent Japanese Kana, and further superencyphered with a book of random-number ‘additives’ that was changed at intervals. In essence, it seems, the encryption must be neutralized, at least in part, to even see the code, which then had to be analyzed for patterns to narrow down to the possible meanings of the number strings.
The original JN-25 was instituted 1939, which U.S. cryptanalysts had made some progress on before it was replaced by the JN-25B version, essentially a new code, on Dec 1 1940
Q1) minor question - why was it not called JN-26? Is it a different code altogether, or a variant of the first? Did the change invalidate the previous progress?
As it appears so far, subsequent changes that frustrated cracking efforts were not with the code itself, but with the encrypting additive books. This occurred at intervals – once in early 1941, again on June1, again on August 1, and again on Dec 4, just before the surprise attack. If I understand right, the code-breaking progress until then is still valid and ready to proceed once the cipher is cracked anew.
Q2) Is this correct, or did the additive changes alter the underlying code, invalidating previous work?
Evidence it was not broken by US cryptographers appears pretty strong: Budiansky claims to have found multiple primary sources detailing the actual progress on the code and its ciphers, indicating that no JN-25 transmissions were read as current intelligence prior to Dec 7. This may be an oversimplification (eg; there may have been particles of useful intel, rather than none, so far as I know), but it seems to me essentially correct.
Contradictory evidence is weak; Robert Stinnett – whose work seems to be full of flaws I’m beginning to latch onto - claims the US had broken the code entirely by mid-November 1941 at latest. His main evidence for this is a letter he found that seems to say something else entirely – something closer to “we’re trying hard to break the code.” http://www.nybooks.com/articles/14086
So it appears the US, at least in the known channels of analysis (Hypo, Cast, etc.) did not get more than a smidgen of the code readable – but there were people other than the US working it, especially the British and the Dutch. James Rusbridger and Eric Nave claim the British broke the code and were able to read JN-25 messages at will well before 12/7. The whole thing sounds fishy but I haven’t looked close yet.
Q3) Can anyone debunk the British JN-25 decode prior to 12/7 proposal before I do and save me work?
It may mean nothing, but the 1946 Congressional joint committee's report made no mention of JN-25, or any Japanese coding system. Decodes of intercepts were possible by then, but not called on as evidence – the Japanese plans were instead assembled from memories of their military survivors, and some stray copies that escaped destruction. Adm. Layton found in the 1980s the National Security Archive had “no JN-25 traffic that was actually decrypted before war broke,” “not one single original decrypt made at the time of any JN-25 message” and even looking at later decodes “we evidently did not pick up Yamamoto’s 25 November sailing message” at all. Layton also found British official sources equally non-forthcoming on 1941-era JN-25 decodes. [See “And I was There” available for reading online – pages 206-207, 231-32, 534]
Q4) Am I reading Layton right, that this very important order is not in the archive as received?
Q5) Does anyone have any newer information on where a pre-Dec 7 intercept can be seen so we can see what a “10-15%” readable message looks like?
I have other questions and thoughts for later, but this should generate enough answers to keep me busy for a while.
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