NEWS: Fatal Flaw In Code Bought Japan's Navy Down In World War 2

An Australian mathematician has revealed for the first time, fatal flaws in the Japanese Fleet's World War 2 naval code. Dr Peter Donovan has said he is the first to discover the truth since documents previously kept secret by Britain, U.S.A and Australia were made available in 1975. The code JN-25 used groups of numbers that were multiples of three and it was a flawed process that was exploited by the allied forces.



The code flaws were being discussed ahead of Australia's 60th aniversary of a hard fought victory by the allied forces in the Pacific.

Unfortunately the code was cracked to late for the events surrounding the bombing of Pearl Harbour in 1941 but certainly enough to maybe give the allies the edge to win the war of the Pacific.


[edit on 9-8-2005 by Mayet]

[edit on 9-8-2005 by Mayet]

Good find. No doubt next to the Manhattan Project one of the least mentioned exploits of the war was in the Signals Intell arena. From the US efforts in the Pacific to the Joint US/UK efforts against the Germans Enigma code machine at Blechley Park, these efforts saved countless lives without every firing a shot.

"cracked too late for the events surrounding the bombing of Pearl Harbour in 1941"
I have a read a wealth of evidence to the contrary, we knew it was comming...

www.google.com
In 1994 the NSA published that JN-25B was completely cracked in December 1940.

www.the7thfire.comIn January 1941 the US gave Britain two JN-25B code books with keys and techniques...

"...everything that the Japanese were planning to do was known to the United States..."
-ARMY BOARD, 1944

By 1942, the Allies were beginning to read the code, the next stage after cracking it.

By that time the Japanese had revised the code several times, but it was still based on the same flawed code book.

Cracking the code came too late to prevent Pearl Harbour in 1941 but it gave the Allies a leg-up in the Coral Sea Battle of 1942 and provided knowledge about the Japanese advance in what was then New Guinea in the same year.

I would like to hear more because according to the official line quoted in the article from the documents even though they had parts of the code it wasn't quite cracked in December 1941.

Now thats just the official line. I would be interested to hear some PROOF of this not being so.

Originally posted by Mayet

I would like to hear more because according to the official line quoted in the article from the documents even though they had parts of the code it wasn't quite cracked in December 1941.

Now thats just the official line. I would be interested to hear some PROOF of this not being so.

As I recall the US Navy used a decoy message in late May 1942 that the base at Midway Island had a broken water condenser and was short on fresh water. An intercept of this message is what convinced Nimitz to send his carriers out to Midway. The rest is history. If they were able to read the whole code there would have been no need to send the decoy message. However if they could only read parts of it the water condenser message must have contained some of the sections that they could read. For proof of this I reccomend reading "Miracle at Midway" by Gordon Prange

Originally posted by JIMC5499

Originally posted by Mayet

I would like to hear more because according to the official line quoted in the article from the documents even though they had parts of the code it wasn't quite cracked in December 1941.

Now thats just the official line. I would be interested to hear some PROOF of this not being so.

As I recall the US Navy used a decoy message in late May 1942 that the base at Midway Island had a broken water condenser and was short on fresh water. An intercept of this message is what convinced Nimitz to send his carriers out to Midway. The rest is history. If they were able to read the whole code there would have been no need to send the decoy message. However if they could only read parts of it the water condenser message must have contained some of the sections that they could read. For proof of this I reccomend reading "Miracle at Midway" by Gordon Prange

I remember that story as well. We knew a decent amount of the Japanese codes. We had their diplomatic codes cracked before Pearl Harbor, and were decoding their messages from Tokyo to their Embassies around the world before the Japanese embassies themselves could do it.

Anyway, back to the Midway story. We knew, from intercepting their messages, that an attack was coming. We just weren't sure where. So we sent out the message about a water shortage on Midway, knowing the Japanese would pick it up. When they did and when they sent out the message to their forces, we were able to figure out the Japanese code word for Midway. Thus, we put 2+2 together and knew that an attack on Midway was coming. Didn't they also launch a diversion attack on the Alleutians (I know I spelled that wrong!) hoping that we'd bite and send our carriers there?

This is something for all those folks who say Intel and human assets aren't important, and who say spy satellites aren't weapons of war, and that a little propaganda or leaked information on enemy conditions or morale doesn't mean anything.

Every day the world Media gives out more information free and clear about responses to terrorism and attitudes on the home front, than we gathered through stealth and guile and great risk over months during any of the World Wars. Have they forgotten "loose lips sink ships"? Or do they act with purpose?

With just little bits of code, much more damage was done to Axis powers than with guns and bombs alone. Uncountable lives saved on *both* sides. Information is the most powerful weapon. And those who gather it deserve more recognition than they'll ever receive.

Originally posted by Phugedaboudet
This is something for all those folks who say Intel and human assets aren't important, and who say spy satellites aren't weapons of war, and that a little propaganda or leaked information on enemy conditions or morale doesn't mean anything.

Every day the world Media gives out more information free and clear about responses to terrorism and attitudes on the home front, than we gathered through stealth and guile and great risk over months during any of the World Wars. Have they forgotten "loose lips sink ships"? Or do they act with purpose?

With just little bits of code, much more damage was done to Axis powers than with guns and bombs alone. Uncountable lives saved on *both* sides. Information is the most powerful weapon. And those who gather it deserve more recognition than they'll ever receive.

Great Post and very true!

I saw a show on the History Channel where they interviewed a former senior KGB officer who stated that they had full department that were dedicated to going thru copies of magazines, newspapers and books purchased by their embassies in the West.

When I was at my training school in the US Navy in the early 80's I shared a room with two Antisubmarine Warfare Technician trainees. Popular Science published an article about Soviet submarines. I asked one of my roomates if what I read about the Alfa class sub was correct. They both went into a panic. The info in the Popular Science article was considered classified by the Navy.

[edit on 9-8-2005 by JIMC5499]