There is no question traffic analysis played every bit as important a part of intelligence gathering as any other part. This fact was knowledge officially after the 1933 Japanese Navy Grand Maneuvers. Quoting from Duane Whitlock’s, On-The-Roof Gang (OTRG) member, Class #20, “The Silent War Against The Japanese Navy.”
In preparing to cover the Grand Maneuver, LT Wenger, USN who had been attached to the staff of Commander in Chief Asiatic Fleet (CINCAF) as Radio Intelligence Officer, arranged to receive all of the intercept material from Station “Shanghai (A), Guam (B) and Philippines (C) and from two or three temporary intercept sites. Given the task of deriving intelligence from the material by all methods short of cryptanalysis, LT Wenger spent the next six months performing post-facto traffic analysis. Out of the effort he produced a 115 page report of the Grand Maneuver in which he laid out in considerable detail the composition and disposition of the forces involved including the identity of the individual ships and commands participating (Naval Order of Battles).
His report was sent back to Washington where it took the small cryptanalytic staff laboring there another three years to recover enough of the new code to affirm that the report produced by LT Wenger was essentially accurate. From CAPT Holtwick’s History of the Naval Security Group, “The success of ‘traffic analysis’ in giving a picture of the 1933 maneuvers, without the information later from decryption, completely sold the idea of Radio Intelligence to CINCAF Admiral Upham. The lessons were taken seriously and resulted in a letter from CINCAF which made strong recommendations for the establishment of a major decrypting center in the Ultimate Defense Area and recommended an eventual location on Corregidor Island.” Corregidor is located in the entrance of Manila Bay, Philippines.
Source: NCVA/ Carl Jensen
Edited By Mario Vulcano
20 May 2024 at 19:19
During a cruise around the “western half” of Japan (all points southwest of Tokyo) last year, we visited Sasebo among other ports of call. When we were offered the opportunity to take a bus tour of “World War Two relic sites”, we jumped on it. The first stop was a ruin of a substantial concrete bunker-style facility about an hour out in the countryside (there is still some of that, in THIS part of Japan – reminded me of Misawa!…but, I digress). Turns out this was the actual site of the fleet broadcast transmission used by the IJN throughout the war. In fact, literature distributed at the site indicated that not only was this the actual site from which the famous “climb Mount Niitaka” signal was broadcast, ordered the Pearl Harbor attack to go forward, but it was one of only two such sites supporting the entire Navy (the other was at Truk. After the capture of Singapore, the Japanese repurposed its intact comms-transmit facility as a third fleet broadcast site, operational from February 1942).
As for the site at Sasebo, it consists of three enormous reinforced-concrete monoliths which suspended the long-wire transmit antennae, each of which terminated in the bunker, which enfolded all generator, transmitter, coding and other functions. There were (and still are) a couple of cottage-style shacks for non-operational functions scattered around the site. There is a nifty scale model of the site while in operations located in the (now-empty) generator room.
As a piece of WWII-SIGINT-flavored history, this place is hard to beat! I recommend it!
Bill Gravell, CAPT, USN (ret)
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20 May 2024 at 20:57
Looking forward to the rest of this series! It wasn’t that terribly long ago that TA-103 (Traffic Analysis) was still a required course to be eligible for advancement, at least for linguists (can’t speak to the other CT ratings). At some point the cryppie community divested from traffic analysis, but I’ve always believed that if the cyber warriors are able to do what they say they’ll be able to do, we’ll all be going back in time and this skill will suddenly (but not unexpectedly!) become absolutely necessary again!
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