New article on ULTRA in the Med

A very interesting article regarding the effects of ULTRA intelligence against the Italian Navy’s supply convoys is available from the Naval War College Review.

The article is ‘The Other Ultra: Signal Intelligence and the Battle to Supply Rommel's Attack toward Suez’ by Vincent P. O'Hara and Enrico Cernuschi. The authors are critical of the view that codebreaking allowed the Brits to sink Rommel’s supplies and stopped the Axis advance towards Egypt.

According to the authors: ‘This article examines the impact of intelligence in the war against Axis shipping in the two months leading up to the battle of Alam el Halfa, which concluded on 2 September 1942. It demonstrates that Ultra information was not always accurate or timely and that Hinsley overstates Ultra ’s impact by crediting it with sinkings that had nothing to do with either signals intelligence (SIGINT) or traffic to Africa. It also casts light on the role of the Italian navy’s intelligence service, the Servizio Informazioni Segreto (SIS). The SIS provided intelligence that often offset the timely and relevant Ultra SIGINT that Britain did possess. Its code breakers enabled Supermarina, the operational headquarters, located in Rome, of the Regia Marina, the Italian navy, to read, often in less than an hour, intercepted low-grade radio encryptions from British aircraft, and, more slowly, first-class ciphers from warships and land bases. Supermarina’s communications and command system disseminated information in near real time, thereby amplifying the operational value of its SIGINT. This is a fact that the British were unaware of at the time and that has remained virtually unknown since.’

ULTRA intelligence and Rommel’s convoys

One of the most important questions regarding the war in North Africa, during WWII, is what effect did the sinking of Axis convoys have on the overall campaign.

Can Rommel’s defeat be attributed to his lost supplies? Or were the losses tolerable?

It is an important question not only in the context of military operations but also because the intelligence that allowed the Allies to monitor the convoy movements came from decoding Italian secret communications. Specifically messages enciphered by the Italian Navy’s Hagelin C-38 cipher machine.

As such many authors and even the British official history ‘British intelligence in the Second World War’ mention this achievement in glowing terms and argue that it was of immense importance.

Is that true? Did Bletchley Park’s success with the C-38 have strategic implications?

The answer is yes and no.

It is undoubtedly true that the movements of the  Italian convoys could be followed by decoding their messages. For anyone who doubts that ‘British intelligence in the Second World War’ vol2 has an entire appendix ( Appendix 17-‘Contribution of Sigint to Axis shipping losses on North African route June to October 1942’ ) which lists Axis shipping sunk and the decoded messages that betrayed their journey.

The main source of information came from decodes of the C-38 cipher machine. This was a model built by  the Hagelin company and sold to many countries around the world. During WWII several countries used it for secret messages, including Italy, Portugal, Sweden and the USA. In American service it was called M-209 (slightly modified version).

The C-38 was a small but surprisingly powerful cipher provided that it was used well. If the internal settings were changed each day and if messages with the same indicator were avoided then it was very hard to ‘break’.

Unfortunately for the Axis it seems the Italians seriously misused it and thus made the British work much easier. According to a British report : ‘The very serious mis­use of it - monthly change of internal set-up, and change of slide about twice a week - robs it entirely of security’ [Source: J. J. Eachus, memorandum (nd), ‘Hagelin, as used by Italians’].

Moreover it seems that messages were frequently enciphered with the same settings so these ‘depths’ were used by the British codebreakers to recover the true settings. A ‘crib’ frequently used on those depths was ‘KSUPERMARINAKALTK’ (K was a word separator). [Source: Colossus: The secrets of Bletchley Park's code-breaking computers, Appendix 4]

In order to speed things up a cryptanalytic device named Nightingale was built and used by the British.

Thanks to these decoded messages the movements and often the contents of the convoys could be recovered in time for measures to be taken against them.

So that part of the story is clear, in which case why did i say no earlier?

Having the information is one thing. Using it is another. In order for secret intelligence to be of use in the field it is necessary for a military force to have the means to attack the enemy. In the first half of 1941 and 1942 the Brits had the information but could not attack the convoys because they lacked the necessary ships and aircraft.

Malta was used as a base for British planes and warships which attacked Axis shipping. When enough planes and ships were available they took a heavy toll on convoys. However when that happened the Germans intervened with their Luftwaffe (Fliegerkorps X  and later Luftflotte 2) and temporarily neutralised the island. This happened in the first halves of 1941 and 1942.

British efforts to move supplies and war material to Malta reversed the situation and allowed the German and Italian forces to take a heavy toll of British convoys.

Thus for long periods of time the Axis were able to transport large quantities of equipment unmolested even though their convoy routes were known to the enemy.

The other major issue is that even when the Allies made a major interdiction effort, against the convoys, the Italian Navy was able to transport the majority of supplies to N.Africa (in 1941-2)

Initially i was under the impression that the majority of supplies were sunk en route, at least that was the general impression that i got from books and articles. However a detailed look into the convoy statistics taken from the most official source ‘La Marina Italiana Nella Seconda Guerra Mondiale’-(1972) makes it clear that this was not the case.

Let’s have a look at the statistics:

Supplies by type:

Supplies by recipient:

It’s obvious that the Italians were able to transport safely the overwhelming majority of the supplies. The total is 84% for both years. This is true both for the first halves of ’41 and ’42 when the British could not effectively intervene and for the second halves when they did.

However that does not mean that the British efforts did not have an effect. There is definitely a fall in the percentages. For first half ’41 we get 94%, for second half 73%. For 1942 the numbers are 94% and 74%. If we look at specific categories then we can find cases where there is a significant drop in the supplies received.

In 1941 the main outlier are fuel shipments in November and December .During those months a British naval force operating from Malta was able to attack and destroy Italian convoys. One of their most successful operations took place on the  night of 8-9 November. As a result in November only 8% of fuel supplies are received. However due to bad luck on 18 Dec ’41 the naval K force (2 cruisers plus 2 destroyers) operating out of Malta drifted into a minefield and out of 4 ships 2 were sunk and 2 heavily damaged.

In 1942 the major German effort to neutralize Malta through bombing was successful and allowed Italian shipping to cross the Med without problems. In the second half however British efforts resumed and we can see from the stats that fuel shipments were affected. In percentage terms we get 97% for first half and 63% for the second. If we look at absolute numbers it’s 134,585t versus 113,559t, a decrease of 16%. This doesn’t seem to me to be a loss of strategic proportions.

Especially in the period July-November 1942 an average of 22,300t of combustible liquids are successfully transported. These would be enough for the Axis forces if they had chosen a defensive strategy and stayed close to their supply ports.

It should also be made clear that when books conflate lost with not arrived (as in ‘British intelligence in the Second World War’ vol2, p422) they are making a big mistake. Not arrived ≠ lost. Convoys were often ordered to return to port when ships or planes had revealed their position.

I hope that from the information presented so far it is realised that Rommel’s eventual defeat cannot be attributed to inability of the Italian navy to transport his supplies. The numbers are clear. Instead the main problem for the Germans was their inability to supply their forces far from their supply ports (mainly Tripoli and Benghazi). This problem has been analysed quite extensively by the renowned military historian Martin van Creveld in ‘Supplying War: Logistics from Wallenstein to Patton’.

German efforts to shift the blame for their defeat in N.Africa to their Italians allies were ungentlemanly.

Despite their faults the Italians fought as well as could be expected from them .The Italian Navy especially managed to transport the war supplies to N.Africa and fought with distinction throughout the campaign.

In the end the solution of the C-38 was a major advantage for the Allied side. Misused by the Italians it supplied first rate intelligence on the convoy routes. However that information did not have strategic consequences, as the British forces could not mount an effective interdiction campaign for long periods of time and even when they did most of the supplies always got through.

Acknowledgements: I have to thank Andreas Biermann for the convoy data and Ralph Erskine for giving me the information concerning British efforts vs the Italian C-38.

General Gamba and the Soviet diplomatic code

In a previous post I looked into the possible compromise of the Soviet diplomatic code during WWII. The Germans had managed to recover a copy of Code 26 from the Soviet Consulate at Petsamo in 1941.

In a follow-up I had a look at more clues, including a British report that the Italian secret service could read the ‘Russian confidential cypher’.

This time I have found correspondence between General Gamba, head of the cryptanalytic department of the Italian Army’s Intelligence Agency - Servizio Informazioni Militari and Colonel Kempf of OKW/Chi.

Gamba in his messages mentions the Allied codes given by him to the Germans and makes some requests. One of them was the Soviet diplomatic code. But what could he make of it? Since the SU used one time pads to encipher the code even by having the codebook he would not be able to solve one message.

The German also responded along these lines: ‘The diplomatic ciphers have not been worked on for several years because the complicated subtractor recypherments make any success illusory’

The only way that he could use the Code 26 was if he had managed to get copies of the enciphering pads. Is that why he persistently requested the Soviet code?

Unfortunately this is just a theory. However the British message of 1943 mentions success with the Russian code. The only way the Italians could have read the OTP would be to have access to both the codebook and the enciphering pads.

Here is the relevant report TICOM D-71 - 'German and Italian Correspondence on Miscellaneous Cyphers'

An easy target - Italian codes and German codebreakers

Italy was, during WWII, the second member of the Pact of Steel. Italian military units fought side by side with the Germans in N.Africa and in the Eastern Front. However this camaraderie did not prevent the Germans from reading their ally’s codes.

In fact Italian codes were a major target of the German codebreakers from the 1930’s till 1943, when Italy surrendered to the Allies.

The agencies that exploited Italian codes were:

1.     The Foreign Ministry’s cryptanalytic department – Pers Z S

2.     OKW/Chi

3.     The Forschungsamt

4.     The Army’s OKH/Inspectorate 7/VI

All were quite successful in their work as the Italians were considered to have bad cipher security.

Since compromised Italian codes were a danger to German military units that operated close to them, the Germans tried to get them to upgrade their codes but this did not produce the desired outcome. In one case when a German cryptanalyst told them their codes were insecure he was locked in a room until he could prove it by decoding a message!

The Germans were also interested in the encoded communications of the Vatican. The Pope’s cryptographers however seem to have performed better than their military counterparts, as German successes were limited.

More information is available from the ‘European Axis Signals Intelligence’ volumes and from TICOM reports.

Pers Z

From EASI vol6 – ‘The Foreign Office cryptanalytic section (Pers Z)’  , p29 and p33

Italy. Work on Italian diplomatic codes was an outstanding Pers Z S achievement. From 1935 until late 1942, with lapses as new code books were introduced, Pers Z S apparently read all major Italian diplomatic codes. The 1940 reports from the Italian Group listed twelve codes, enciphered or unenciphered , all of which were read. The work became increasingly difficult in 1942-1943, for the Italians introduced bigram substitution over the additive on the basic code books, ‘’If the basic books  had been changed ,the traffic would have been impossible to read”. Some systems 'Were read after the collapse in 1943. Mention was made of Badoglio double transposition system which was never solved. Dr. Paschke mentioned three Neo-Fascist systems which were read in the latter stages or the war.

Vatican The 1940 Report of the Italian Group (Paschke) made it clear that while approximately 50 per cent of the Vatican traffic could be read, the traffic was not a major PerS Z S commitment. Reference was made to a onepart, three-letter code, enciphered by a transposition within the groups, and to a one-part figure code, enciphered by means of substitution alphabets and a  sliding strip. Most of the book groups were secured from Goering's "Research" Bureau (FA).

From TICOM I-22 ‘Interrogation of German Cryptographers of Pers Z S Department of the Auswaertiges Amt’, p3

25. Italian: Dr. Paschke was asked what success he had had with Italian systems.He replied that he had been instructed in 1935 to devote special attention to Italian and that the results had been the best imaginable; they had read everything ('Den schonsten Erfolg den man sich denkan kann; es wurde alles gelesen'). In 1942-43 work became increasingly difficult: the Italians increased their subtractor material before the collapse and employed bigram substitution over a subtractor over a book. If they had changed the book, the traffic would have become 'impossible' to read. After the collapse they read a Government code ‘Impero’  recyphered with figures from the encode, with little depth. Later the Government systems were not read for lack of depth, but it was thought that they used double transposition. The Neofascists had used a 5,000 figure subtractor; the peculiar systematic arrangement of the figures in the subtractor assisted solution very much. In the last three months the Neofascists had used unrecyphered books which were easily read, and an alphabetical book with a short subtractor called RA 1.

OKW/Chi

From EASI vol3 -  ‘Signal Intelligence Agency of the Supreme Command Armed Forces’ (OKW/Chi) , p67 and p69

Italy:

Senior Specialist Raffel was head of the Italian desk. The section contained thirty-five to forty people and apparently had considerable success. Senior Specialist Paschke, of the Foreign Office Cryptanalytic Section (Pers Z S), said that between 1935 and 1942 his people had "read everything' in Italian, and it is likely that their results were passed on to OKW/Chi. We know that OKW/Chi read a diplomatic system called AR 22, and the Impero Code. Between 1942 and 1943 the Italians increased their additive material and employed digraphic substitution. After the surrender of the Italian Government, the Impero Code continued to be read by the Foreign Office Cryptanalytic Section (Pers Z S) for a while. Later, there was no longer sufficient depth to do this  and it was suspected that a double transposition was being employed. The systems of the Neofascist Italian Republic were also read by the Foreign Office Cryptanalytic Section (Pers Z S). They used a 5,000-figure additive; during the last three months, they also used unenciphered books and an alphabetical book with a short additive called RA 1.

Vatican, Greece:

Around the beginning of the war, a desk was established for attacks on Vatican traffic. Seifert, a former member of the Austrian Cryptanalytic Bureau, joined OKW/Chi at the time of the Anschluss and broke a Vatican book.

From TICOM I-21 ‘Preliminary Interrogation of Oberst  Kettler, R.R. Dr.Huettenhain  Sdf Dr. Fricke and ObIt. Schubert (OKW/Chi), 15 June 1945’, p3

Q: What work did you do on Italian ciphers ?

Huettenhain : We worked on them with success. We told the Italians but at first they refused to believe it.To prove it to them we finally sent a cryptographer to Rome and he was locked in a room until he had done so!

Forschungsamt

From EASI vol7 – ‘Goering’s Research Bureau (Forschungsamt) , p82 and p88

Italian Systems.

Enciphered code ,

Rentschler claimed some success on high grade Italian diplomatic systems. The Annual Report of the Italian Group of Pers Z S for 1940 indicated a fairly extensive Pers Z S - FA cooperation on Italian systems. Intercept of the FA was made available to the Foreign Office and from 1939 through 1940 there was a regular exchange of encipherment tables. In September 1940 and in November 1940 there was a mutual exchange of book groups on two codes AR 38 and RA 1.

Vatican Systems.

Vatican Code.

In  a captured Pers Z S reconstruction of a Vatican Code Book the signature of a Fraulien Titschak appears with the date of August 1939 and a notation that she had copied out values at that time for the FA (Fraulien Titschak was a member the the Foreign Office Cryptanalytic Bureau) .The Annual report of the Italian Group, of Pers Z S for 1940 indicates that while Pers Z S did some work on Vatican systems most or the identifications on Vatican systems were received , from the FA.

OKH/In 7/VI

From TICOM I-78 ‘Interrogation of Oberstlt. Mettig on the History and Achievements of OKH/AHA/ln 7/VI’, p11

This section specialised in watching Italian traffic which was very insecure and most of which was read by the Germans, especially traffic from ITALY to NORTH AFRICA. In 1941 Hptm Dr FIALLA paid a visit to ROME, notified the Italians of their Weakness and requested greater security. In spring 1942 Hptm BIGGI of the Italian Army paid a return visit to In 7/VI and was enlightened as to the German use of Hollerith machines. The renewed request to the Italian for greater security in their cipher methods failed, just as the Italians were unable to set up their own Hollerith section. In 7/VI had not, in any case, the authority to put any pressure on the Italians, moreover, the general opinion was that the Italian cipher department under Gen GAMBA was not competent enough to institute changes; (in  matters of agents' ciphers the Italian section was more efficient). It was assumed by In 7/VI that German troop movements in AFRICA were betrayed to the British by the insecure Italian wireless.

From TICOM I-100 ‘Report by Uffz. Herzfeld of NAAST 5 (Gen. d. NA) on the Work of the Italian Referat of In 7/VI’, p2 :

In the beginning of September 1943 an Italian reciphering table and a number of messages from the cipher office of the Italian Commandantura at ATHENS arrived in BERLIN. They had been taken by some German officers under dramatic circumstances. When the news that MUSSOLINI had been arrested and that the Italian government had concluded on armistice, was received at German Headquarters in ATHENS, two lieutenants of Kommandeur der Nachrichtenauflaarung at NEA PHALIRON drove to the commandantura in ODOS AMERIKIS in ATHENS, walked into the cipher office and started collecting the material lying on the tables in the office and packing it into a case in front of the bewildered cipher personnel. They were in the middle of doing so when a number of Italian officers came in and began shouting rather excitedly. After some controversy the Germans thought it preferable to disappear quietly since the attitude of the Italians became too threatening. They did however carry with them what they had collected from the tables and sent it on to BERLIN where PW was charged with trying to find out what it was worth.

P4 :

PW resumed his work there, but in November 1943 Major LECHNER decided to dissolve the Italian Referat, a decision justified by the fact that after the fall of LEROS no more Italian wireless messages could be intercepted. It was believed that the Allies had prohibited further Italian Wireless transmissions.

In the end Italian cipher security remained low (although some of their high level codes proved too much even for Bletchley Park!) and certainly had unfortunate consequences for them and their German allies. Perhaps the Germans could have changed that by being completely honest with the Italians and presenting them with the full record of their success against their codes. Then again that would mean that they would lose their ability to closely monitor their ally’s moves. Choices, choices….

Bletchley Park vs Berlin – The North African Seesaw

 All told, Britain arguably lost the signals intelligence war in that theatre between January 1941 and May 1942, and certainly did worse and suffered more damage there than it ever did in the Atlantic.

                           Robert Ferris ,‘’ Intelligence and strategy: selected essays’’ chapter 4

In my posts so far I’ve only dealt with the good people of Bletchley Park in the Typex compromise story. Now it’s time to change that and take a closer look at the performance of German vs British  codebreakers in actual campaigns of WWII.

This part will be about the fighting in N.Africa. My goal is to look at the codesystems of both countries and see which side had the advantage and for how long. Obviously I’ll also have to mention the successes each side had with other codes ( Italian ,American, Free French),however my main focus is on German and British codes.

From all the information I’ve seen it’s clear that the German side had a major advantage in the period 1941 to summer 1942 both in high level and tactical systems. The Enigma keys used by Rommel proved to be too much for Bletchley Park and the keys of the German navy in the Med also resisted attack.

The Brits were successful with the Luftwaffe keys used in the Med (‘’Red’’,‘’Light blue’’,’’Scorpion’’ among others) plus the could read Italian codes. They only read Rommel’s key Chaffinch (Chaffinch I : General , Chaffinch II : Comm between Panzerarmee Afrika and higher authority , Chaffinch III : Administrative ) thanks to captured material  in 17 Sept -19 Oct '41 and from 2 Noc -6 Dec '41 ,with some regularity and  often a week or more late. The operational Enigma key of Panzerarmee Afrika Phoenix (for use between Army,Corps and Divisions) was captured during Crusader (18 Nov ’41) and traffic read up to 23 Nov ’41 , then not broken until summer ’42.

The Chaffinch key was broken again on 10 April 1942 when 50% was read with a delay of a week or more. For the rest of ’42 all three keys were broken but with differing degrees of success. On average half the days were ‘broken’ and half of the breaks were achieved within 48h after receiving the messages.

June was also the month that the Phoenix key was broken  but it was usually read after a delay of several days.

Here are the detailed statistics concerning British success with German army ‘keys’ in N.Africa in 1942:

German army 'keys' broken by Bletchley Park -N.Africa 1942
Month	Chaffinch I	Chaffinch II	Chaffinch III	Phoenix
Jun-42	2	11	20	16
Jul-42	6	16	13	7
Aug-42	8	15	13	16
Sep-42	14	19	14	25
Oct-42	18	22	21	27
Nov-42	17	28	23	18
Dec-42	12	14	19	12

 

It should however be mentioned that at the same time that Bletchley Park was finally able to decode Rommel’s Enigma ‘keys’ another means of communication had become available to him. This was a microwave link from Derna, Libya to Athens, Greece via Crete. From there communications could be routed to Rome and Berlin. As far as I know this link was secure from eavesdroppers.

Regarding naval Enigma the U-boats in the Med used a modified form of the Home waters key from 1^st October 1941 .GCCS was able to read their traffic till the key was changed in February 1942.Then no success until December 1942.

Surface ships and shore authorities in the Med and the Black Sea used the Porpoise key, which resisted attack until August 1942. By September it was being read regularly.

During the campaign low level Italian military codes were read continuously but their high level codebooks proved more secure (almost completely in 1942). The main problem for the Italians was that their naval machine ciphers were decoded and resulted in the sinking of convoys carrying supplies to Rommel’s forces. The machines in question were the commercial Enigma and the Hagelin C-38 (the main culprit).

While the Brits unsuccessfully tried to read Rommel’s communications ,the German codebreakers were  decoding messages in British high level systems :

The Army’s War Office Cypher (Army universal high-grade codebook, carried traffic between Whitehall, commands, armies, corps and, later, divisions) was read in the Med area from summer 1941 to January 1942.It gave accurate information on  8^th Army’s strength and order of battle. The information on British tank strength seen in German decoded messages was so accurate that the War office ‘’was very concerned’’. [Source: British intelligence in the Second World War vol2,p298]

The RAF Cypher (high-grade codebook) was read in the Med from early 1941 until November 1942.Most messages were solved ‘’within 5-10 days’’ according to Voegele chief cryptanalyst of the GAF.

The RN’s Code and Cypher plus low level codes were read. According to report ADM 1/27186 messages in Naval Code No1 were read in 1941.In May ’41 a copy of Naval Code No1 was captured from HMS York ,sunk in Suda Bay Crete. It’s successor Naval Code No2 was broken in 1942 and a high proportion of traffic recoded by Auxiliary Vessels Tables was read.

The more high level Naval Cypher No2 (in use from Aug’40 to Jan’42) and No4 (used from Jan’42 to June’43) were also compromised. A summary of B-Dienst’s success with them follows :

1.     Naval Cypher No2 :First read Sept '40.Oct' 40 setback (change in encyphering procedure) .From March '41  until Sept '41 limited ~10%, ,from then on  high.

2.     Naval Cypher No4: First read March '42.By Oct '42 reconstructed. Messages relating to convoy movements in the Pacific ,Indian ocean and Red sea were read.

The Interdepartmental Cypher (used by Foreign Office,Colonial,Dominions and India offices and the services. Also used by Admiralty for Naval Attaches,Consular Officers,Reporting Officers)  was read extensively. It allowed the Germans to keep track of negotiations between Turkey and Britain. [Source: HW 40/85]

As if all these compromises were not enough the Brits were the victim of one of the most embarrassing episodes of the war. The American military attaché in Cairo colonel Bonner Fellers continuously transmitted (in the Military Intelligence Code) British plans , appreciations and strength and loss reports.

The Free French were also guilty of using faulty codes but Fellers telegrams were so important that everything was organized to intercept them and decode them in the fastest way possible. From early 1942 until July he was unintentionally providing the Germans with invaluable information.

In the tactical field the Brits did even worse. Due to the lack of a machine cipher for division downwards they had to rely on hand ciphers of limited security. They also resorted often to radio telephone communications that offered no secrecy. Attempts to disguise their conversations by using code words did not usually hinder the German eavesdroppers.

Unfortunately these security lapses on behalf of the British forces meant that  Rommel’s intelligence unit NFAK 621 ,headed by the able Captain Seebohm, was much more successful than it ought to be.

By solving low level codes , overhearing British commanders talk on the radiotelephone and using direction-finding and traffic analysis they were able to provide Rommel with a more or less accurate Allied  order of battle. The effect of this unit was a major multiplier of German military strength.

Especially in conditions of mobile warfare ,when messages were exchanged quickly with little regard for security ,Seebohm’s men gave Rommel the edge.

Their loss in 10 July 1942 when the unit was overrun by the Australian 2/24th Battalion crippled Rommel’s signal intelligence capability at a moment he needed it most .

So how did the Brits manage to win that campaign? From what I’ve mentioned so far it seems they were seriously beaten in the intelligence field ( in the period 1941-summer 1942)

First of all both sides were able to get some information about each other’s strengths and dispositions from various sources ( aerial photo-reconnaissance ,spies , army recon units , low level codes ,traffic analysis and D/F ).  Also both sides made mistakes and miscalculations from the intelligence they got. But more importantly there were many more factors influencing victory and defeat than merely signals intelligence.

Rommel’s main problem was his inability to provide supplies for his forces at long distances from his supply ports.Even though the RN was able to sink a lot of Italian supply ships the problem was not lack of supplies but inability to transport them far from the ports. This fact is discussed in detail by Martin van Creveld in ‘’Supplying War: Logistics from Wallenstein to Patton’’ . Rommel’s trucks burned more gas than they were carrying to the front because of the long distances involved. No amount of codebreaking could change that….

Even though Rommel was defeated at El Alamein he only managed to get so far with the help of signals intelligence. His reckless style of command would have led to disaster without this ‘’hidden ace’’. Such successes however heavily depended on silly British mistakes.

After July 1942 things changed fast. Once the British forces captured Seebohm’s unit they realized the extent of their compromise and immediately changed their signal procedures and codes. From then on the Brits would be considered ,by the Germans ,to have the most secure signal communications of any  Allied nation.

In the second half of 1942 the Germans not only lost their access to the British code systems that I mentioned earlier but  practically all their codes were being read. By reading Rommel’s keys the Brits got the strength reports for his troops and vehicles. The biggest success of Bletchley Park was a decoded signal sent to Middle East Command on 17 August 1942.This was  ‘’perhaps the most important single item of information that the Enigma had yet contributed to the desert campaign’’ [Source: British intelligence in the Second World War vol2,p298]. The decrypt of a Panzer Army appreciation ,It contained an outline of Rommel’s intentions for the coming offensive.

However the location of his units was not revealed from the Enigma :  No Enigma decrypt giving a comprehensive account of the Panzer army’s dispositions was obtained after 30 April 1942 ; that of 30 April -a Chaffinch decrypt- showed that the bulk of the enemy’s armour was in the north, but mentioned that some  elements of the DAK were ‘at the moment’ operating at the south of the line ‘to secure the southern flank’. [Source: British intelligence in the Second World War vol2,p722]

How was Rommel able to save his forces from annihilation and retreat to Tynisia in good order ? The answer is the same as before .Signals intelligence although of great importance cannot win battles. The Germans still had well equipped ,well trained and well led troops and they did not hesitate to move new units to Tunisia to counter the Allied landings.

In Tunisia the field was leveled as the American forces were very careless with the use of radio. The Free French forces also continued to make mistakes and use insecure codes. Still after a few successes the Axis forces were defeated.

So what are the lessons to be learned from the North African campaign?

First of all it is more important to protect your own codes than it is to read the enemy ones. The Germans definitely did much better than they should have against British codes in N.Africa. If the Brits had a machine cipher in widespread use for forward units things would definitely have been different for Rommel .A simple machine like the Hagelin C-38 if used correctly would be beyond the capability of his mobile unit NFAK 621 and messages could only be solved at higher headquarters with significant delay if at all. A small number of speech scramblers would also have meant that his units would have been destroyed in June 1942.

It is also apparent that codebreaking is important but not decisive. Having information is of no use if you can’t exploit it to your benefit. For example by reading Italian naval codes the Brits were able to sink a lot of supply ships. However due to bad luck on 18 Dec ’41 their naval K force (2 cruisers plus 2 destroyers) operating out of Malta drifted into a minefield and out of 4 ships 2 were sunk and 2 heavily damaged. This disaster coupled with the Luftwaffe campaign against Malta meant that during the first half of ‘42 the Italian navy was able to transport supplies virtually unmolested despite the Allies knowledge of their routes and schedule.

Rommel’s successes can definitely be attributed in some part to his superiority in signals intelligence but that advantage would have meant nothing if his forces didn’t also have good equipment , communications , logistics and training.

In the end the German successes with British codes have to be attributed in part to poor security on the part of the Brits. They continued to use codebooks that they knew were in German hands , they used tactical codes that were easy to solve and for inexplicable reasons they used the radiotelephone as if they were back home talking to a friend. Once these silly errors were corrected and once Bletchley Park started solving German army and navy enigma keys the roles were reversed .In a month Rommel’s best source of intelligence dried up for good.

Authors and academics that present the Ultra story in triumphant terms should take a good look at the N.African campaign and the defeat of Allied codes in the period 1941-summer 1942. The people at Bletchley Park were not the only ones skilled in codebreaking.

Sources : Intelligence and strategy: selected essays , British intelligence in the Second World War vol2 , Ticom reports: I-112 , I-113 , I-51 , War Secrets in the Ether , Rommel's intelligence in the desert campaign, 1941-1943 , FMS P-038 German Radio Intelligence , CSDIC SIR 1704 , American Signal Intelligence in Northwest Africa and Western Europe , HW 40/85

Acknowledgments: I have to thank Ralph Erskine for the Chaffinch and Phoenix key statistics.

Olivetti cipher teleprinter

An interesting event is described in Ticom D-60 which contains private papers of Dr Erich Huettenhain chief cryptanalyst of OKW/Chi.

In January 1943 the Italian Navy demonstrated a cipher teleprinter to German military authorities in Rome.This machine had seven  wheels.Five enciphered the respective Baudot impulses and the other two acted as the drive for the rest.

The Germans had a crypto-expert among the crowd but did not inform their Italian allies of this.Their conclusion was that the teleprinter was not up to the standards required by the German armed forces.It could be solved with a message of 6.000 characters or several adding up to 10.000.

Was the teleprinter actually used in the field ? The only other reference I have is from ‘’Colossus: the secrets of Bletchley Park's codebreaking computers’’  p472 :

Much less is known about the practical use of a cipher teleprinter machine built by the Olivetti company (Italian patent 387 482, 30 January 1941). This had five cipher wheels and two motor wheels, producing only a weak irregularity.