EXAMPLES OF INTELLIGENCE OBTAINED FROM CRYPTANALYSIS 

1 August 1946 

Declassified and approved for release by NSA on 10-29-2013 pursuantto E .0. 1352a 

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INTRODUCTION 

The following examples are selected from the files of 

the Army Security Agency to illustrate the different kinds 

of information obtained from cryptanalysis of enemy messages 

and, where possible, the action taken and results achieved •. 

Two of the examples also indicate the importance of protecting this source of information. 

I. Japanese Army Systems 

A. The Hi-81 and the M-2? Convoys, November 1944 

II. 

B. The Japanese Attack on Ai tape, 10 July 

c. The Tachibana Maru, summer of 1945 - Japanese Military Attache Systems 

A. Japanese description of the ~Nest 'Vall 

November 1943 

B. The OSS in Lisbon, 1943 

III. German Diplomatic Systems 

A. Oscar Hellmuth, Secret Agent, 1943 

B. Cargo of Monte Albertia 

IV. German Low Echelon Army Systems 

1944 

A. Signal Intelligence Operations in the Field 

V. Japanese Navy Systems 

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I. Japanese Army Systems 

A. The Hi-81 and Mi-2? Convoys, November 1944 

1. On 14 November 1944 the First Transport Staff in 

Moji sent a cryptographdradio message to the a~rforce units concerned requesting air escort for two convoys, the Hi-81 and 

Mi-2?, carrying troops to reinforce the Philippines. According 

to the message, which was read by the Army Security Agency, one 

of the convoys consisted of ten ships, tankers and escort ves-

.sels; it was to leave Mutsure on the 15th; the route, including 

noon positions from the 15th through the 22nd, was given. 

(Jll925) The convoys immediately encountered difficulties. According to a series of Japanese Navy messages which were read 

by the United States Navy, the Akitsu YlB.ru was sunk by a sub-· 

marine on 15 November. (15/11/44 151? JN14?G} On l? November 

the Hi-81 reported being sighted by a B-29, with strong indications that the Mi-2? had also been sighted. (17/11/44 1611 

JN14?G) Four hours later the Mayasan Maru was torpedoed. (l?/11/ 

44 2002 JN147G) The final score for both convoys according 

to messages read by the Army Security Agency, was six ships definitely sunk, one ship disabled and one ship on fire. (J32?3, 

J3259, J44932, Jl6120, Jl6852) The diaries of two of the survivors, which were later picked up in the Philippines, confirmed 

the information obtained from the messages on the serious damage 

inflicted on the convoy and added that one aircraft carrier was 

also sunk. (Advatis Bulletins nos. 303 19 Feb 45 and 343 27 

Feb 45) 

2. This episode may be used to illustrate another important aspect of the work of obtaining intelligence from enemy . traffic. The careful study of the external aspects of messages 

by the sections dealing with traffic analysis made it possible 

to recognize a convoy message in raw traffic, and to concentrate 

all efforts on translating it in time to be of use. 

3. Another point illustrated by the history of the 

Mi-81 and Mi-2? convoys is the method adopted to protect the 

source of information. The sighting of the convoys by B-29's 

explained to the enemy ~&e submarine attack. 

B. The Japanese Attack on Aitape, 10 July 1944 

1. A summary of the Aitape-Wewak operations in the 

summer of 1944 illustrates how useful this type of information 

may be in making estimates for the planning. of operations. 

Messages read early in the year at Central Bureau, Australia 

showed the status ot Japanese forces in the area between Madang 

and Hollandia; the existence of acute supply problems was revealed .and the number of front line troops together with the 

state of arms and equipment was given. The subsequent withdrawal 

of these .units into the Wewak area was not unexpected to the 

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American comm.and. By the end of May the Japanese found their 

position untenable and decided to attack. A 28 May message, 

which was translated by the Army Security Agency on 1 June, 

mentioned supplies needed by the 18th Army, controlling operations in eastern New Guinea, which must arrive at Wewak by the 

end of June in order to be of use in "the attack on Aitape." 

(Fl3408) A 20 June message from the 18th Army translated 25 

June, supplied the information that an all-out attack againsttk~ 

US Aitape perimeter was to begin about 10 July. The message 

gave the detailed disposition of each division under the command of the Army with the planned operations of each division 

in the attack; total strength of the forces involved was stated 

to be about 20,000. (Fl9959) 

2. The information was forwarded to the Commander in 

Chier, Southwest Pacific Area. The Japanese atte.ck was made 

on schedule, and the results were reported in a message of 13 

August: According to the report of the Japanese Commander, 

most of the enemy artillery had been destroyed, the units decimated. The seriousness of the supply situation was shown by 

the description of how the.v had made their ten days supply of 

rice last twentyfive days: "By resorting to chewing it raw instead of cooking it, the period of consumption had been prolonged somewhat." The Command.er concluded that, "Unless we can 

impress upon the enemy the ~reatness of the defensive strength of the Japanese Army, thereby striking terror into his heart, 

it will be impossible to defeat the enemy." (F25591) 

c. The Tachibana Maru, summer of 1945 

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i 1. Early in 1945 it became apparent from read1-ng Jap- ~ anese traffic, that the enemy was attempting to redeploy their 

forces in the Netherlands East Indies. One of their objects 

was to withdraw units from the Banda Sea area to the comparative safety of Java and Sumatra. By June however laclc of 

available water transport led them to try to make use of a hospital ship, the Tachibana ~' for purposes other than those 

prescribed by the Geneva Convention. (J?4668) The ship was 

renamed the Hirose Maru (J71916) and assigned to transport 1500 

troops of the 11th Infantry Regiment with 150 tons of ordnance 

and munitions from Tual in the Kri Islands to Surabaya. (J??56?) 

Precautions taien to provide against the possibility of search 

by an enemy vessel included supplying hospital clothing for the 

troops, having available daily sick reports and lists of medical 

supplies (J7?56?) and sending the regimental colors by air. (~89766) The ship left Tual 1 August, scheduled to reach Surabaya on the 5th. (J91835) 

2. According to the New York Times' account however, 

the Tachibana, although marked by floodlighted red crosses twenty 

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feet high, was halted north of Timor by two destro.vers. The 

discovery by a·search party that cases marked medical supplies 

contained munitions, while the only wound among the hospital patients was the result or a packing case being dropped on a 

thumb, led to the capture of the ship. (Nfilv York Times, 5 Aug 45; 8 Aug 45) 

3. Fully one month before this attempted deception, 

information about the Japanese plans for the unorthodox use of 

the hospital ship had been received from messages. Other messages translated in July made it possible to give the Navy 

exact information on ports of arrival and d~parture and loading 

and sailing times. Again the source was concealed by attributing the sighting of the ship to air reconnaissance. (New York 

Times, 8 Aug 45) 

II. Japanese Il..alitary Attache Systems 

A. Japanese Description of the West Wall, November 1943 

1. The value of intercepted diplomatic and ~ilitary 

attache traffic for military intelligence purposes is illustrated by quotations from the report of Colonel Ito, attached to 

the German Western Area Headquarters, who made the report after 

inspecting the Atlantic coast defenses in the autumn of 1943. 

In the construction and location of fortifications, 

emphasis is mainly on the defense against landings at 

and the protection of the naval bases, especially the 

five submarine bases of Brest, L'Orient, St. Nazaire, 

La Rochelle and Bordeaux ••• The harbors, large and small, 

have been fort:I.fied with emphasis on the proper weapons 

and defenses for each particular location. We have confirmed the fact that defenses of places other than those 

with cliffs and precipices have all been fortified for 

more than 1,000 meters from the shore line. In the 

places where there are cliffs and precipices, a sharp 

lookout is kept. They have· arranged things so that 

troops are held in reserve in the rear and can be imme·dia tely sent in as reinforcements ••• In order to protect 

her submarine bases and harbors, Germany has not only 

constructed defenses against sea attack, but has made 

powerful l,and front defenses ••• consists in constructing 

for several kilometers from the harbors defensive positions which connect nests of resistance and strong 

points. This defense varies in depth for the various 

cities as follows 

La Rochelle ••• 10 to 15 kilometers 

Le HaYre ••• 6 to 8 kilometers 
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Cherbourg ••• ? kilometers 

Boulogne 4 to 5 kilometers 

Dieppe 2 to 3 kilometers 

Examples of the tYJ>es of army and navy coastal type guns 

used on the sea front in the defense of harbors: 

200 

La Rochelle district - four 60 caliber mm./naval 

guns; four 35 caliber 

--m-- --m-- --m-- mm. 

army guns. 

Royan district - four 280 mm. naval guns 

Le Havre district - four 300 mm. guns 

SHTEA.BURAW'A (kana version of place name. May 

be Cherbourg) district - four 

380 mm. heavy field pieces ••• 

In order to eliminate dead space in the neighborhood 

of the strong points, they have two or three grenade 

throwers firing from within the armored turret (?range?) 

20 to 600 meters; speed of fire - 120 per minute; 

caliber, 50 mm. --g-- --g--. These are high-angle fire 

weapons. For defense against tanks, tank ditches 

(built in triangular cross-section with a span across 

the top of 5 meters and a depth of 3.5 meters} are constructed along the periphery of the strong points. In 

addition to having flanking fire provided by 2 or 3 

casemates with 40 mm. Skoda anti-tank guns (?similar 

to?) machine guns·and 2 or 3 casemates with 60 caliber 

50 mm. anti-tank guns, the~ have·2 or 3 gun shelters 

(Protected against bullets) with 60 caliber 5<Jfum. antitank guns which they can drag out into the open to 

fight when the opportune moment comes. They also have 

mine fields in front·of and behind the tank ditches 

(anti-tank mines, anti-personnel and horse mines, etc., 

are used together; they are laid in three rows of 2 

mines each for each 3 square meters). As far as infantry obstacles are concerned, in addition to the mine 

fields, they have wire entanglements both in back of 

the tank ditches and within the strong points. For the 

direct protection of the casemates, fixed-type flame 

throwers are buried in the ground nearby and set ·Up so 

that they can be electrically ignited from the ringstelle. 

( D3348) . 

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B. The oss in Lisbon 

1. General Marshall in his letter to Governor Dewey of 

25 September 1944, gave as an exampie of "the delicacy of the 

situation" that "some of Donovan's people (OSS), without telling us, instituted a secret search of the Japanese Embassy , offices in Portugal. As a result the entire military attache 

Japanese code all over the world was changed, and though this 

occurred over a year ago, we have not yet been able to break 

the new code and have thus lost this invaluable source of information, particularly regarding the European situation." (~ 

York Times, 8 December 1945) --2. A series of Japanese messages, read by the Army 

Security Agency, givesa behind the scenes picture of the repercussions of this episode. The OSS although misguided, apparent- ly carried on their operations with some skill, since the first 

news that "American espionage agency in Lisbon knews minutest 

details of activities of Japanese ministry there and also has 

the Japanese codebook" came from the Italian General Staff in 

Rome (Rome/Tokyo, 6/29/43, #88542; Rome Circ. 6/29/43, Dl318) 

and was· a complete surprise to Morishima, the Japanese minister 

in Lisbon. He assured Tokyo that "code books ••• could hardly 

have been stolen, because of careful precautions ••• Perhaps," 

he suggested, "You mean some of the messages were deciphered." 

He naturally wished to know the source of-the Italian information. (Lisbon/Tokyo, 6/30/43, #88649) This point was never 

settled, according to the correspondenceJbut it was suggested 

that the report might have come from " ••• an Italian resident 

in Lisbon who has contacts with British and US Intelligence 

Agencies." The Japanese Legation continued to assert that it 

was impossible that " ••• their materials could have been seen 

by any unauthorized person." (Lisbon/Tokyo, ?/2/43, D-1316) An 

investigator, however 1 was sent to Lisbon where he was "re.sented and ill-treated." \Madrid/Tokyo, ?/12/43, #89812) Morishima 

then offered his resignation (Lisbon/Tokyo, 8/25/43, #95040) 

and his fellmn-minister in Madrid thought it "only natural that 

he should be indignant and utterly discouraged" at this highhanded treatment. (Madrid/Tokyo, 8/26/43, #95095) 

3. Although this ill-advised attempt to procure a copy 

of a codebook which was already being read apparently had results, they were not as disastrous as General Marshall's letter 

indicated. The code was not changed but on 18 September 1943, 

the Japanese introduced a new and more complicated system of 

enciphering the code. By the beginning of December of the same 

year, however, the new key had been solved and messages in the 

Japanese military attache system were again being read by the 

Army Security Agency 

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III. German . .. Diplomatic . _' System 

A. Oscar Hellmuth, Secret Agent, 1943 

\____... 1. The Blue Book on Argentina, the United States Government off icia! indictment of the fascist regime in that 

country, emphasizes strongly the importance to the cause of 

the Allies of the arrest of Oscar Hellmuth. In 1943 the Argentine Government was negotiating with the Nazis in order to 

obtain German arms which were to be used to strengthen Argentina 

in her position of refusing to break relations with the Axis. 

Accordi..og to the Blue Book the negotiations "culminated in Octtober 1943 in the ill-starred Hellmuth mission ••• The Argentine - Government and Himmler's secret intelligence agents in Argentina 

selected Oscar Hellmuth, an Argentine national, as their common 

representative· to enter into broad negotiations with the German 

Government in Berlin, not only for arms, but for many other 

types of mutual assistance. The mission failed but only because 

of Hell.rnuth' s arrest en route by the Allies." He ·was removed 

from the ship on which he was travelling to Spain by British 

authorities in Trinidad in October 1943. (N.filY Yor_k Times, 26 Jan 

1944) 

2. It is possible that the information which led to 

Hellmuth' s arrest c.ame from a message read by the Army Security 

Agency, which was sent by the German Charge d•Affaires in Buenos 

Aires to Berlin, 30 September 1943, in which he reported the 

intention of the Argentine Government to send Hellmuth~ described as a co-worker of the Germans in Buenos Aires, via Spain to 

Berlin where he was to be received by the Fuehrer. {99937) 

This message was translated 24 October, six days before the 

arrest of Hellmuth in Trinidad. Coast Guard messages supplied 

the name of the ship on which he sailed. (CG #2125, ? Oct 1943; 

CG #2183, l? Oct 1943) 

B. Cargo of Monte Albertia ~·- ---- 1. According to the ~ tQU Times, the Jfi.:inister of 

Economic "Narfare announced in London in November l943 that some 

weeks before "five ships plying between Buenos Aires and Spain 

were halted at British control points for search with the following melodrrunatic results: 40 drums stated on navicerts as containing paste were found full of liver extract, an important 

base in food compound for U-boat crews. Twelve drums had false 

bottoms and embedded in each was a disk of platinum three inches 

in diameter and weighing a pound, worth more than $4,000 a piece 

but worth a king's ransom to Germany as a factor in the manufacturing of nitroglycerine for explosives. Also in the cargo 

were six tons certified as bacteriological peptone when in fact 

they were stuffed with small containers of gland extract powder 

for the treatment of shock. In making public this discovery the 

British showed what they and the Americans, with whom they are 

in close touch, are up against, as well as how the system is 

working. (New York Times, 10 Nov 1943) 

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2. A series of messages between Erich Otto Meynen, 

the German Charge' d'Affaires in Buenos Aires_,and Berlin, which 

were read by the Army Security .Agency, revealed very clearly how the smuggling system worked. Ships officers or Argentine 

nationals were found who were willing to act as agents; (99954, 

105329, 97119, 101652, 99630) their chief function, apparently, 

was to deliver the consignments to the German consul in the 

first harbor which the ships touched. (105329, 101652) In a 

·message of 16 August 1943, translated 30 August, the arrangements 

for the cargo sent on the Monte Albertia, a Spanish cargo ship, 

were described: 40 boxes which had been declared as containing 

bile paste really consisted of "extract"; twelve of them had 

false bottoms covering 56 kilograms of platinum. Six boxes which 

supposedly consisted of peptone in reali'ty contained pituitary / 

extract. ( 95049) __/ 

IV. German Low Echelon Army Systems 

A. Signal Intelligence Operations in the Field 

1. The Operational History of the 849th Sign.al Intelligence Service, Mediterranean Theater of Operations, describes 

the nature of the intelligence produced' by radio intelligence organizations, which attacked enemy low and medium security 

traffic in the field. In comparatively static periods, ~ttended by low volumes of radio traffic, information obtained from 

these types of enemy messages tended to deal with such topics 

as strength reports and ammunition returns, artillery and mortar 

fire orders, relief of personnel and changes of position, patrol 

activity and location of enemy units and positions. Intelligence 

of this kind made it possible to maintain a constant check on 

enemy activities, intentions and dispositions; to keep order of 

battle files up to date; and to know in advance of proposed 

Allied targets and possible enemy target points, on the basis of 

which the latter were often shelled or bombed successfully. 

During times of tactical activity, when radio activity also, of 

course, increased, enemy traffic supplied up-to-the-minute, play 

by play descriptions of engagements, often before the information was received fr·om Allied troops, and betrayed enemy· intentions and relocations before their actual execution. 

2. Some illustrations of this type of intelligence 

and the use to which it was put are taken from the account of 

the operations of Detachment E, 849th SIS, in Italy: "As the 

Allied forces crossed the Volturno the mobile 3 Panzer Grenadie·r Division was identified on 12 October as coming into the 

line suggesting that it was to cover further withdrawal and 

that' the enemy did not intend to make a stand at the river line. 

Three days later the line was revealed to run generally from 

Am.eglio to Allan to s. Mass.ima." (p. 42) "When the enemy inland 

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forces were withdrawing along the main route across the Mignano 

bridge, Allied bombers attacked the bridge the morning of 29 

October, but could not determine the damage. By noon the Hermann 

Goering Engineers code was broken and revealed that the bridge 

had been destroyed beyond immediate repair and that traffic was 

to be re-routed through Conca. Early that afternoon the enemy 

alternate route of withdrawal was put under attack and bottled 

up." (p. 43) At Anzio: "Early realizing the important part 

artillery was to play in the enemy attempt to contain the beachhead, changes in the operating. set-up were effected which brought 

the application of Signal Intelligence to a peak of effectiveness. 

Single isolated messages would not suffice. Detailed records 

were kept of each individual enemy group, of every location, 

mission and the number of rounds fired. Four of the Intelligence 

Staff men were assigned to keep a constant watch on voice frequencies. Although the enemy re-enciphered the code some five 

times, continuity in reading the code was maintained throughout 

the operation. So detailed was the tabulation kept of radio reperts that at any given time it was known just how many rounds 

a given bettery had expended or how much ammunition it had received, or what its alternate position was. So close was the 

liaison with Allied counterbattery that enemy reports of Allied 

fire were used as correction data for Allied firing guns." (p.44) "On 24 May with the main VI Corps attack northward toward Cori, 

messages on the 105 Flak Regiment net showed that some 4 or 5 

of its Battalions were located between the 335-355 northings and 

912-961 eastings. Since this unit had been operating in a ground 

anti-tank role, it clearly showed that the enemy expected an 

armored thrust to the Northwest, which indeed was the plan. At 

about this ·time the decision was ma.de to move troops over the 

mountain, which soon hopelessly split the enemy forces." (p. 45) 

3. Similar examples may be found in the Third Army 

Radio Intelligence Historl in Campaign of Western Europe, p~epared by Signal Intelligence Service of Headquarters Third w.s. 

Army. For instance, "As early as D-day itself, reconnaissance 

traffic of the 21 Panzer Division was intercepted on the English side of' the Channel indicating the formation's committment 

in the Caen sector." (p.31) "Headline news on 31 July came 

with the disclosure that 2 SS Panzer division headquarters was 

located at Montbray, and on the same day the need of ammunition 

by the Division's artillery regiment was expressed in traffic 

of that formation." (p. 32) "Reconnaissance patrols of 21 

Panzer Division on the 16th of August provided the highlight of 

activity to that date giving extensive reports on the situation 

at the south end of the Falaise Gap. 2 Panzer Division was mentioned as 'the left flank neighbor', and tanks of the 9 SS 

Panzer Division were reported in Lacourbe and Montgaroult. The 

reconnaissance missions of this group shifted the following day 

to'-an area east of Falaise and continued their conveniently detailed reports indicating that it was one of the prinicpal units 

covering the withdrawal east from the gap to the Seine." (p. 34) 
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"The high point of the month's spot intelligence came on the 

evening of 28 September at 1815 hours when a reconnaissance 

patrol announced that Battalion 'Schneider' would attack on 

the following morning at 0600 in the vicinity of Foret de 

Gremmercy to establish contact with its left neighbor. As the 

reconnaissance traffic reported the next day, this attack was 

repulsed." (P. 40) 

4. The mission assigned to Signal Security Detachment 

"D" was the procurement of signal intelligence from the solution of tactical codes and ciphers for the Acting Chief of 

Staff, G-2, 12th Army Group.(Summarz of Operational Activity, Si~al Securit~ Detachment "D" for the Period 1 September l944 

to _ April 194 • ) ''DUring the German Ardennes offensive, 

messages from thirteen divisional and similar formations in and 

near the 'Bulge' was read. Since the formations represented the 

bulk of the armored and mobile formations employed by the Germans during the Ardenne operations and constituted the major 

threat to Allied forces, the intelligence gained from their messages not ·only indicated accurately the trend of enemy operations 

carried out by all enemy units within the ~Bulge' but also provided G-2 with reliable information at a time when other intelligence sources were relatively unproductive or non-existent." 

(An Analysis of Ciro-Pearl Intelligence derived ~ German ~ 

filgnal Communications .!2l_ Signal Security Detachment "Q" during ~Period 10 August 1944 - 12 ~ 1945. p.2} "In early September 1944, when the German Armies were rapid'ly retreating 

through eastern France and Belgium to the Siegfried Line, 2 SS 

PZ. Div 'Das Reich' was retiring southeastward from the line: 

Dinant-Liege, Belgium. On ? September 1944, the Div Ia (operations) of 2 SS PZ DIV announced to Div elements that: 'The 

Allies have presumably reached Liege from the ·Nest. 12 SS PZ 

Div "Hitler Jugend" now has its furtherest fol"\.vard Outguard 

Line of Resistance west of Hamoir." The usefullness of this 

information at a time when Allied elements were feeling out an 

otherwise confused situation in the Liege area was immediate." 

(ibid, pp. 4-5) "During the rapid retreat of t~e German armies i~ance and Belgium in September 1944> 9 PZ Div ••• communications of 28 September announced the location of a large fuel 

and ammo dump ••• in the forest 3 km from Villers-Cotterets. 

(Note - the above mentioned dump was the largest supply dump 

captured intact in France. Two German general officers were 

surprised at breakfast when Allied armored forces took the area 

under command.)" (ibid, p. ? } 

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