Maritimes.at

Austro-Hungarian and British Radio Intelligence during the First World War in the Mediterranean

by Nikolaus A. Sifferlinger

Preface

The following article is based on Austrian- and British archive material and international literature. Therefore it focuses on the work of the Austrian-Hungarian radio intelligence concerning all surrounding countries and the work of the British with Austrian Naval Codes.

Little is known to the author of French and Italian work on Austrian Codes and it is hoped that this gap will be filled soon by publications of French and Italian researchers.

 A brief history of Austrian-Hungarian Radio Intelligence from its beginning till November 1918

 Soon after the Austrian naval attaché in Rome reported the successful tests of wireless radio telegraphy between a shore station and naval units by Guglielmo Marconi in La Spezia in Summer 1897[1], the Austrian-Hungarian Navy (k.u.k. Kriegsmarine) decided to undertake its own tests with the new communication invention in 1898.[2]

 

Pic.: Guglielmo Marconi with his equipment onboard the Italian vessel N.8 during the tests in La Spezia in July 1897 (Rivista Marittima)

 During Spring 1898 first tests took place in Vienna[3] and in December 1898 wireless Marconi systems were successfully communicating between the costal-defence-ship BUDAPEST, the torpedo vessel LUSSIN and the costal fortress Fort Musil at Pola. The installation was only temporary, no technicians of the Marconi-company were present and distances of 8 km were covered. The k.u.k. Kriegsmarine was convinced that wireless telegraphy was of great importance for naval communication from now on.[4]

 

Pic.: Austrian-Hungarian costal defence ship BUDAPEST, which hosted the first successful radio tests in December 1898 for the k.u.k. Kriegsmarine

 The years 1899 until 1902 were used by the k.u.k. Kriegsmarine for the evaluation of the different radio systems. The following systems were tested: Marconi, Schaefer, Slaby-Arco, Siemens-Braun and Rochefort.

Following the tests and the fact, that the, at that time, superior Marconi system was offered to the k.u.k. Kriegsmarine at 52.000 Kronen in 1902[5], compared with the Siemens&Halske system costing only12.500 Kronen[6], the navy decided to introduce the German system in 1903.

During tests with the system Schaefer between the armoured cruiser KAISER KARL VI., the old battleship TEGETTHOFF, the torpedoboat CONDOR and the coastal fortress Fort Musil, the first intentional radio interference exercises were done on 29 September 1900, with the TEGETTHOFF causing the interference by transmitting on the same frequency to interrupt communications between KAISER KARL VI.. This was done from different positions and distances, in order to evaluate the effects of active interference.[7] From now on this radio interference exercises were a fixed part of the k.u.k. radio communication training at sea.

In October 1901 the common Triplex-Signal-book between Italy, Germany and Austria-Hungary was established, in order to permit communication between the three allied fleets at that time.

In March 1903 the battleship HABSBURG and the costal defence ships WIEN and BUDAPEST were fitted with the Siemens-Braun radio system with good results. Siemens-Braun and Slaby-Arco was transformed into the new German company TELEFUNKEN soon afterwards. Step by step all major Austrian-Hungarian warships were equipped with the TELEFUNKEN-system.

Soon it was realised, that foreign radio communication could be read, if it was not coded.[8]

On 14 May 1904 the Austrian naval attaché in Rome reported, that the commissioning of Marconi-radio stations at the Italian coastline was due any day and on 15 May 1904 the k.u.k. Kriegsmarine instructed the active fleet (Eskadre), that “from now on all own secret radio-transmissions must be coded”.[9]

When in late May 1904 the Austrian radio station on the island of Sansego got contact with the Italian station Ancona, the Austrian Kontreadmiral Julius Ripper and the naval-technical-comité (Marinetechnisches Komitee) reported:

“In case of a crisis or war the own transmissions must be coded to block unauthorised receivers from the information; during peace time the use of the own codes shall be reduced to a minimum, in order to avoid giving the other side material for decoding.”[10]

From this time on the own important radio traffic was coded and foreign traffic was monitored. Received messages were put forward to the Center of Naval Intelligence at Pola, the “Marineevidenzbureau”, which collected and tried to identify origin and content of the messages.[11] from 1904 onward. The own radio traffic was monitored to insure that codes were used correctly and not compromised.[12] In 1908 the Italian Navy used a mix of clear text and figure-code.

 

Pic.: Italian radio signal from 19 March 1908 as received from the Austrian torpedo depot ship PELIKAN and forwarded to the Marineevidenzbureau (Kriegsarchiv)

 In order to deal with the growing amount of radio information, the Marineevidenzbureau asked for the assignment of a radio officer on 7 September 1908 and Fregattenleutnant Franz Leist[13] was detailed for this work soon afterwards.[14]

When Austria-Hungaria annexed Bosnia-Hercegovina on 5 October 1908 and causing a major crisis, the navy was instructed to monitor the movements of foreign warships by radio-analysis very closely.[15]

In June 1909 the Naval Technical Commitee (Marinetechnische Komitee) evaluated the new direction finding system of Bellini-Tosi, and realised the value of determining the position of foreign radio stations.[16] But it would take until 1916 till the k.u.k. Kriegsmarine got its first radio direction finding stations.

The k.u.k. Kriegsmarine also monitored the German radio traffic, as an example a message of the German cruiser GNEISENAU, then off Malta, is shown here. Since the German Code was not known one could not read the message at the time.[17]

 

Pic.: Coded radio signal of the German cruiser GNEISENAU off Malta, which was monitored by the shore station (Landradiostation) Pola during the night of 19 November 1910 (Kriegsarchiv)

 

The Intelligence Bureaus of the Austrian-Hungarian Army (Evidenzbureau des k.u.k. Generalstabs) and of Austrian-Hungarian Navy (Marineevidenzbureau) worked together very successful in the field of radio intelligence.[18] The navy monitored and collected the foreign radio traffic and the group of decypherers in the Evidenzbureau worked on the solution of the codes. The code-breaker group (Chiffrengruppe) in the Evidenzbureau of the k.u.k. Generalstab was formed in 1911 headed by Captain (Hauptmann) Andreas Figl.

During the war between Italy and Turkey in 1911/1912 most radio traffic was monitored by the k.u.k. Kriegsmarine and the armoured cruiser KAISERIN UND KÖNIGIN MARIA THERESIA played a key role cruising in the Aegean Sea and recording foreign radio traffic.[19]

 

Pic.: Austrian-Hungarian armoured cruiser KAISERIN UND KÖNIGIN MARIA THERESIA in Aegean waters, successfully monitored foreign radio communications

 In December 1911 the decoding of the foreign messages was ordered by the Austrian-Hungarian War Ministry (k.u.k. Reichskriegsministerium)[20] and early in 1912 the k.u.k. Marineevidenzbureau could report details on the Italian Telegraph Code book[21].

 

Pic.: Details of the Italian Code Book as found as solution by Austrian Radio Intelligence in early 1912 (Kriegsarchiv OK/MS 270 ex 1912)

 On 16 February 1913 the radio officer of the k.u.k. Kriegsmarine, Linienschiffsleutnant Franz

Leist presented his memorandum “Radiotelegraphy in war – Radio traffic against enemy interference”[22] to the fleet command, which was handed to all ship commands.

In January 1914 the k.u.k. Kriegsmarine was interested again in the direction finding radio system Bellini-Tosi and even investigated if it could be mounted onboard ships.[23] It was expected that such a device would give good service for naval reconnaissance at sea. But on 4 December 1914 the Telegraphenbureau of the k.u.k. Kriegsmarine made the decision to stop the introduction for technical reasons[24]. It took until 1916, when the fleet command (Flottenkommando) put force behind the introduction of radio direction finding stations and a working radio direction finding network was set up. This was a major disadvantage for the Austrian-Hungarian radio intelligence work during the first two years of war.

When the First World War started in August 1914 the Austrian-Hungarian Radio Intelligence branches were well prepared, with the k.u.k. Kriegsmarine depending in decoding on the good cooperation with the specialists of the Army´s k.u.k. Evidenzbureau. The Italian code books “Cifrario Rosso” and “Cifrario Tascabile” had been “bought” by the Intelligence section before the war started and the Serbian Codes had been solved.

A department for dealing with the foreign codes was set up after the outbreak of war (Chiffriergruppe) at the Telegraphenbureau of the k.u.k. Kriegsmarine at Pola, consisting of the following staff:

5 December 1914: Linienschiffskapitän Theodor Skerl Edler von Schmidtheim, Fregattenkapitän Karl Koss, Fregattenkapitän Viktor Nikolits, Korvettenkapitän Alois Baborszky;

6 November 1916: Linienschiffsleutnant Otto Wassich, Linienschiffsleutnant Anton Mayerweg, Major Rudolf Pfeifer von Inberg, Hauptmann Artur Penso, Hauptmann Rudolf Steppan, Hauptmann Emiro Brill, Oberleutnant Gustav Kanz;

26 August 1918: Major Rudolf Pfeiffer von Inberg, Linienschiffsleutnant Anton Mayerweg, Linienschiffsleutnant Otto Wassich, Hauptmann Rudolf Steppan, Hauptmann Emiro Brill.

 

Furthermore the Navy Section (Marine-Sektion) in Vienna had since the begining of the war[25] also a department dealing with own and foreign cyphers (Chiffren-Bureau). On 6 November 1916 its staff consisted of: Linienschiffskapitän Karl Wettstein, Linienschiffskapitän Guido Kottowith Edler von Kortschak, Linienschiffskapitän Alois Bachich von Recina, Korvettenkapitän Alfred Zacharias, Linienschiffsleutnant Leopold Vernouille.

Based on its own radio intelligence experience for most of the actions of the k.u.k. Kriegsmarine either radio silence or feint radio traffic(“verschleierter Radioverkehr”) was ordered.[26] When by 1916 the k.u.k. Kriegsmarine had clear indication of the Allied direction finding network, strict radio silence was ordered for most activities. In the confined waters of the Adriatic this was no major problem, but the submarines had to break radio silence, when they reported their return and asked for instructions (mine-fields, enemy activities etc.) how to enter the home ports.

The own radio traffic also interfered with the radio listening stations monitoring the foreign traffic, but this could be reduced to an acceptable level soon.[27]

In 1914 and 1915 most of the decoding for the k.u.k. Kriegsmarine was done at the Evidenzbureau of the k.u.k. Generalstab in Vienna, which meant that radio messages had to be sent to Vienna for solution and then back to the naval bases and units for utilisation of the information. This was time consuming and therefore the navy started in 1916 to work on the codes at Pola too.

The key person for breaking of new Italian codes was Hauptmann Andreas Figl[28], who was fluent in Italian, and was in charge of the de-coding organisation in the South-West Front command from 22 May 1915 (Frontkommando Südwest in Marburg). The radio intelligence work on the Austrian-Hungarian side was known under the code word “PENKALA”.

On 5 June 1915 Andreas Figl solved the first Italian Code, the “Vocabulario telegraphico”.[29]

 

Pic.: Hauptmann Andreas Figl

Unfortunately most documents of the Austrian-Hungarian Radio Intelligence were either destroyed by the end of World War I together with other secret documents by the own specialists or seized by the alliied forces entering the harbours after armistice. According to Paul Halpern, in the files of the Ufficio Storico della Marine Militare, which were seized at Pola in November 1918, there are also decoded Italian radio messages.[30]

But some of the decoded messages survived in other files of the Kriegsarchiv in Vienna.

The success of the Austrian-Hungarian code-breakers were of greatest importance on the land fronts with Russia, Serbia and Italy. For the naval actions, they gained importance with the defeat of Serbia in late 1915 and the allied retreat to Albania in early 1916.

Most of the sorties of the k.u.k. Kriegsmarine to interrupt the traffic between Italy and Albania in the Winter 1915/1916 were prepared on results of air reconnaissance, submarine sightings and radio intelligence.

As an example the radio intelligence message of the Marine-Sektion (Navy Headquarter in the War Ministry in Vienna) to the I. Torpedoflottilla from 1 December 1915 is quoted, which states that from a decoded message from the 28 November the Duke of Abruzzi asked for reconnaissance between San Giovanni di Medua and Cape Rodoni looking for mines, submarines and warships.

 

Pic.: PENKALA-message from 1 December 1915 from the Marine-Sektion in Vienna to the I. Torpedoflottilla. The message was distributed to all unit commanders (Kriegsarchiv B 1209).

 

The decoded message regarding a convoy to Durrazzo triggered the raid of the cruiser HELGOLAND and five destroyers on 29 December 1915, which led to the destruction of LIKA and TRIGLAV by mines and the major action across the Adriatic Sea.

 

Pic.: Cruiser HELGOLAND

 

The importance of the radio intelligence during the Winter 1915/1916 showed the need for the k.u.k. Kriegsmarine to do the decoding work at Pola and Cattaro in order to get faster results, rather then sending all material to Vienna for decoding solution.[31]

Under the guidance of Linienschiffskapitän Alois Bachich and Fregattenkapitän Alfred Wilhelm the decoding group at Pola was set up at a bigger stage in March 1916[32] and by 25 May 1916 the army officers Hauptmann Artur Penso, Hauptmann Rudolf Steppan and Oberleutnant Gustav Kanz were detached to the Chiffrier-Gruppe at Pola[33]. They all spoke Italian and were trained by the team of Hauptmann Andreas Figl in code-breaking.

 

Pic.: Memorandum of the k.u.k. Armeeoberkommando from 3 March 1916 regarding decoded Italian radio messages (Kriegsarchiv)

 

Pic.: PENKALA (decoded radio message) from 27 Februar 1916 (Kriegsarchiv)

 

In March 1916 the first radio direction finding station of the k.u.k. Kriegsmarine was tested at the Molo V in Trieste with good results.[34] Afterwards a chain of 6 radio direction finding stations was set up during 1917 at the east coast of the Adriatic.

By 8 August 1916 the k.u.k. Kriegsmarine had definite proof of the allied direction finding network on the other side of the Adriatic Sea by a seized document and ordered strict radio silence whenever possible[35].

In June 1916 the Evidenzbureau solved the code of the Russian Black Sea Fleet, on 24 September 1916 the general Russian Naval Code and in January 1917 the new Russian Naval Code.[36] This was of no importance to the k.u.k. Kriegsmarine, but for the allied Turks and their “new ships” ex-GOEBEN and ex-BRESLAU of great importance.

 

Pic.: Italian and British radio messages monitored by cruiser HELGOLAND on 18 October 1917

 

The German Navy did set up a decoding station[37] at Pola for assistance of their submarines.

From 1917 until the end of the war radio intelligence was used to monitor the traffic of the allied forces of the Otranto Strait barrage. According to Max Ronge the Austrian-Hungarian radio intelligence had in 1918 difficulties to achieve solutions of the allied naval codes, which can be contributed to the much improved coding methods.

 

Pic.: Linienschiffsleutnant Otto Wassich, one of the members of the de-coding group at Pola

 

In July 1918 a new Italian Code book was seized in Albania and enabled to read the Italian radio traffic at the Albanian front.[38]

According to Max Ronge the following solutions were achieved at the Italian front in the last months of war:

Country	Chiffre	In force	solved by
Italy	C-S-A	1 August 1918	26 September 1918
Italy	C-S-B	5 August 1918	14 August 1918
Italy	Rosso speciale III	11 September 1918	15 September 1918
France	C-S-8	1 September 1918	4 September 1918

 

When the k.u.k. Kriegsmarine was handed over to Jugoslavia on 31 October 1918, the naval radio intelligence ceased, but the army radio intelligence worked until the 3 November 1918, when the armistice came into force.

In order to deny allied forces any advantages by evaluating the solution processes, the Austrian-Hungarian radio intelligence specialists destroyed much of their material, but still a lot was sized by the victors as will seen in the following part.

As a résumé can be said that the important successes of the Austrian-Hungarian radio intelligence were mainly on the land fronts against Russia, Serbia and Italy. In the Adriatic Sea it helped most of the time to allocate the enemy forces and therefore prevented enemy surprises to the own forces, unless the enemy kept radio silence. Probably the biggest influence was that out of own experience the k.u.k. Kriegsmarine knew about the threats of enemy radio intelligence and started the war with strict enforcement of radio discipline and ever changing codes during the whole engagement.

 

British Naval Intelligence Work on the Austrian-Hungarian Naval Cyphers 1914 – 1918

 

Although prior to the First World War there was a “busy trade” with secret documents in Europe and once a “code book”, which was copied in the Austrian-Hungarian War Office in Vienna (k.u.k. Reichskriegsministerium), was offered to the Russians, none of Austria-Hungary´s enemies seem to have taken advantage by such a buy before the war.[39]

 

During the First World War allied radio intelligence concentrated on two major areas:

a) Radio Direction Finding of enemy radio stations at sea, especially submarines

b) Decyphering of enemy radio messages

 

In the Public Record Office in London there is a substantial British Admiralty document in handwriting dealing with “Austrian Naval Cyphers”.

ADM 137/4684 on “Austrian Naval Cyphers” was written by radio intelligence experts of the famous Room 40[40] after the first world war and gives an detailed overview of the British work on the Austrian codes. ADM 137/4684 is the base for the following article and extensive use is made of the original file[41], being commented by other sources known so far by the author.

ADM 137/4684: “In 1915 (UC 12 ?) was sunk in the Gulf of Taranto on one of her own mines and the Italians recovered from her the old 3 letter German Signalbuch and an Austrian Fleet Code.”

The German submarine UC 12 (under Austrian-Hungarian flag) sunk on 16 March 1916 off Taranto and was salvaged by the Italians in April 1916 and the above mentioned code books were recovered[42]. Italy send copies of the code books to her allies France and Great Britain.

The Austrian-Hungarian Navy had suspected, that when the Austrian submarine U 12 sank off Venice on 12 August 1915, which was recovered by Italy in January 1916, and after the loss of the destroyer LIKA in shallow waters on 28 December 1915 and the wreck searched by Italian divers, the code books may have compromissed. Therefor the codes were changed in August 1915 and January 1916.[43]

 

Pic.: Burning wreck of the destroyer LIKA in shallow water

 

ADM 137/4684: “Subsequently other books came into our possession after the signing of the Armistice.

A systematic attempt to deal was first made by ID 25 in August 1917, though both the French and  Italians had previously decyphered a certain number of early signals using the material recovered from the above mentioned submarine.

When ID25 first studied the subject the last decyphered message was dated May 1916, when at which times the cypher was changed and after which date no attempt had been made to deal with the signals.”

In France it was Captain (army) Georges Painvin, who worked with success on the Austrian-Hungarian Naval codes, in Italy Captain (Army) Luigi Sacco was the specialist. Under Sacco there were Tullio Cristofolini, Mario Franzotti and Remo Fedi. Although Luigi Sacco wrote a book on cryptography[44] after the war, not much on the Italian efforts has become known to the author of this article yet.

In Spring 1917 the director of the Intelligence Division of the Royal Navy, Rear Admiral Reginald Hall, visited Malta, Rome and Alexandria. He realised that although France and Italy monitored most of the German and Austrian-Hungarian radio messages, the results in decoding were modest[45]. It was agreed to improve inter-allied co-operation in radio intelligence. Soon afterwards Lieutenant Commander Nigel de Grey, Royal Naval Air Service and a team of specialists from Room 40 were send to Italy. Further crews for Direction Finding Stations (“Y-Stations”) were send too.

 

Pic.: Lieutenant Commander Nigel de Grey

 

Lieutenant Commander Nigel de Grey joined “Room 40” in 1915, spoke French, German and Italian, and in February 1917 he achieved the solution of the famous “Zimmermann-Telegram”, which accelerated the war entry of USA against Germany.

ADM 137/4684: In August 1917 there were two Austrian codebooks in use. One we were able to prove was the old book above mentioned used at the time exclusively by submarines (both Austrian and German) and the other, a new book which ultimately was found to be much of the same character. All the codebooks used subsequently were constructed roughly along the same lines so that the description of the earliest of which we have any knowledge will be taken as a standard and others will be described from it.

Like most early war naval codes this book contained both the W/T and visual signalling codes. It also contained a number of instructions as to the signal principles of signalling and specific instructions as to use in detail with examples and illustrations.

In actual use the book itself was really comparatively simple (a) instructionally and (b) from the cryptographical point of view. Its main feature was an alphabetical numerical vocabulary of ordinary nautical terms, which differed from the German Naval vocabularies mainly in the fact that the Austrian Sea terms are far less stereotypic than German. Five figure groups were used for this section, pages numbered from 100 – 289.

96 words to the page numbered 00 – 99 omitting 47, 48, 98, 99, allowing space for writing in new words. The reminder of the book was built up of (a)List of ships (b) Geographical list (c) Spelling table (d) Clock times (ec) Times and seasons (f) List of proper names (g) a large number of phrase tables dealing with all manner of subjects principally movement of ships, convoys etc. (h) enemy sightings tabularly arranged (i) distances in sea miles, speed in knots, rotation of engines, latitude and longitude, degrees compass and squad chart also tabulary arranged.

(…)

It will be seen from the foregoing that by looking up the telegram to be transmitted in the code book the result would be a series of groups in 4 and 5 figure groups, five figures predominating. As will be seen hereafter, for certain methods of cyphering those groups it was essential to turn the 4 figure groups into five figures. This was done by using a prefatory figure, the arrangement so accomplished that no figure group could have more than one meaning. (…)

Methods of cyphering:

1. 1.      Method:

“1. The earliest known method employed was a follows:

[For the sake of simplicity throughout the following the figures 12345 will be taken as the five figure group resulting from the use of the code book, 123 being the numbers of the page, 45 the number of the word on the page.]

Two cyphering tables were issued set with the code consisting of (a) a list of arbitrary 4 letter words representing all 1 or 2 figures from 0 – 9 and 00 – 99 (b) a list of arbitrary 6 letter words representing 3 figures from 000 to 999.

The five figure group was divided into two parts:

12 / 345

from (a) the value 12 was taken and was represented by some such word as JURY, MAGD, INGO, TUPF

from (b) the figures 345 were transmuted into some such word as APOTEK, CLOSET, KOKOTT, TAPETE etc.

The group was then written down and transmitted for example as JURYAPOTEK.

It will be seen from this that a ten letter pronounceable group was produced. The 6 letter words are known as characteristics the 4 letter words as determinants.

From a decyphering point of view it will be noticed that by the nature of the code for those numbers beginning with the figures 10-28 must have occurred more than any others and therefore it was not difficult to arrive at which words indicated the vocabulary and which the extraneous portions of the book. [The vocabulary was page numbered 100-289.]”

As the code book and the cyphering table for this was recovered from UC 12 in 1916 by the Italians there was actually no guessing necessary to find out the structure of the code book and the cyphering table, and decoding work could start immediately until the code book and/or the cyphering table was changed.

2. Method:

“2. The earlier method was subsequently dropped and the following adopted [this method was still in use when ID 25 attacked the problem]:

The group being 12345 it was first written down:

45123

and then divided and cyphered as above 45 / 123.

From the decypherer´s point of view this resulted in every six letter word representing a page number and every 4 letter word the number of the word on the page. An index of the groups as they occurred soon made that much clear. Both the above methods have been known at the “46” method – a word of 4 and a word of 6 letters.”

3. Method:

“3. This method was first used by the Danube monitors and also it is believed for weather reports but it was not until it was used for the traffic of both Austrian and German submarines in the Adriatic that it assumed any importance. It was the first method to be solved.

The figure group was first as in (1)

12345

and was then split into 3 parts thus:

1 / 23 / 45

The first figure was then cyphered into a 2 letter group from a list covering the figures 0 – 9 and consisted of the following monosyllables viz.: – BA, CI, DU, FA, GO, HU, JU, KO, LI, NO, PU, RY, SO, VY, WI, XI, ZA – the syllable TY was kept for indicating a key recognition group. Certain figures therefore received 2 equivalents.

The two subsequent parts were then cyphered into 2 four letter groups the resulting group being as it might be thus:

RYJURYMAGD.

It should be understood the there were 2 lists of four letter words each equivalent to the numbers from 00 – 99. From the first list the first part was cyphered, from the second the last part.

In all the above methods no system was followed – the values being quite arbitrarily allotted to the word.

Several different versions of the above method were used known by their key groups TYCLYFOMLA, TYANTIUVAC, TYOMLACLYF, TYUVACANTI –

of these TYANTIUVAC and TYOMLACLYF were decyphered the two subsequent ones were never sufficiently used to be more than partially dealt with, the first in the list was obsolete before we began research.

From a decypherer´s point of view it must be remembered that when the solution of TYANTIUVAC was obtained the original book was (for the most part) in our possession and therefore having by analysis determined the meaning of a few words and by applying the resultant figures to other groups in which the same code words occurred it was comparatively easy when sufficient material accumulated to arrive at a complete solution. It was assumed that German boats using this code would say much the same as those in the North Sea which made such words as stehen, punkt etc. mostly certain on analysis. The first real certainity was reached however when a submarine returning made the word BONTNEWYD in clear which was reported from Malta to be the name of a steamer sunk by torpedos on that date. The word before it was taken as dampfer and the word after as versenkt. This with the few words previously guessed made enough material on which to determine (a) that the enemy was using the code book in our possession (b) the method of cyphering (c) enough other groups to arrive at the sense of the message.

It will be seen that this method presumably necessitated all groups appearing as five figure groups – but as the cyphering tables never fell in our hands it is not quite certain whether some of the bigram prefaces represented blank or a figure. For the sake of decyphering this was of course immaterial.”

 

Pic.: Coding table “Worttafel grünzwei (“TYANTIOMLA”)” for the traffic with submarines. To be used by officers only (Kriegsarchiv)

 

4. Method:

“4. By this method the five figure group was first treated as in (2) and then cyphered as in (3). This method was adopted for important fleet messages in Jan. 1918. The key was changed every day. No progress was ever made in decyphering it.”

5. Method:

“A modification of the above only in this respect that a 3 letter took the place of the initial bigram and a 3 letter group replaced the second of the two remaining parts of the words, thus maintaining a 10 letter group. This change was probably made to facilitate W/T work. The key was changed once a week and some progress had been made in the oversetting of one key to another when armistice was declared. It came [the 5. Method] into force on October 1^st 1918.

Methods 3 and 4 usually have been called “244” and Method 5 “343”.

A point that should be noted before proceeding further is that addresses and signatures where in the “46” methods, taken from a different section of the book and consisted of a list with composite 10 letter groups printed against the units, stations, authorities etc. always beginning with the same 4 letter group. For the majority of the period the 4 letter word used was KLUG and the list was changed from time to time. This signatures were also used with methods 4 and 5, though not exclusively.

Having explained the methods of cyphering an attempt will be made to note briefly the modifications made as the book which fell into our hands and the nature of those succeeded it.

As before stated during the period when the submarine key TYANTIUVAC was in force the book we knew was used with but slight modification.

With the appearance of the key TYOMLACLYF in October 1917 the figures of the paragraphs (a) (d) (e) and (i) was changed. A copy of the book in one of its transition stages came into our hands at the end of the war, though it would appear to have been used there for land line work and to have been modified again for that purpose.

On August 1^st 1918 a special book for the use with submarines known as KOD appears to have come into force. The traffic at this time was so small as to be negligible so that it never affected the condition of affairs.”

After the end of the war in November 1918 several copies of Austrian code books were obtained by the British authorities and the author of “Austrian Naval Cyphers” refers to these.

ADM 137/4684: “It is apparently, from a copy in our hands, a modification chiefly by renumbering and modernisation of KODEINS described thereafter.

This completes our knowledge of codes used by submarines in the Adriatic apart from the German codes.

On September 5^th 1916 judging by the date inscribed in the copy in our hands KODEINS came into force. No attempt was made to solve this code and the copy we posses has been rehashed for the use as mentioned above. It differs considerably in detail from the book as in above. The numbering is entirely changed, the numerical-alphabetical principle being retained by blocks only and the words on the page numbered from 00 – 49 and 99 –50, i.e. the right hand column numbers are in reverse order. This applies to all pages of this book and would of course present no difficulty to the decypherer so long as Method (2) was in use. It was done exclusively in order to prevent a reconstruction of the basic figures of the book. The list of addresses and signatures was than provided with numbers as well as with the “KLUG” equivalent, the numbers being taken arbitrarily out of the dictionary pages and a reference to the list being minted against it in the body of the book. The Spelling table and Geographical list were ran into one and the ship list revised. The Clock times were arranged and included every 10 minutes and the quarters of each hour, instead of only the quarters as before. An auxiliary table of prepositions and common words was added (…)

KODZWEI was apparently introduced on May 1^st 1917 – we have of this only a mutilated copy which has subsequently been used for the construction of KODVIER. So it is some what uncertain as to what its original condition was. There is reason to believe however that it was in all essentials similar to KODZWEI being renumbered and recyphered. This book was partially worked out by the French at the Ministerie de la Marine, partly parallel with and hastily as result of the working load of KODDREI. It never had any but an academic interest.

KODDREI came into force on October 14 1917 as a result of the surrender of TB 11 to the Italians.”

 

Pic.: Frontpage of KODVIER, Telegraphenkodex der k.u.k. Kriegsmarine, in force on 1 July 1918 (Kriegsarchiv)

 

ADM 137/4684: “Its introduction coincided with the change of TYANTIUVAC into TYOMLACLYF. It is unfortunate that no copy of this book ever came into our possession [after the war]. It was attacked simultaneously by the French and by ID 25 and good progress was made with it from the start. In construction the book was similar to KODZWEI though it will be never known how the figures were treated. A prisoner stated in examination that the pages were quite arbitrary numbered which seems probable from the copy of KODVIER which is so made up. He further stated that the numbers on the page were jumbled but that each page was similary jumbled. This may have been so though of course so long as the “46” method of cyphering was in force this made no difference to the decypherer. The code rapidly became legible though the ten groups representing enemy sightings and movements were always obscure as also the lengthy phrases from the phrase book. The auxiliary table was different from that in KODZWEI and its construction was not immediately clear. The order of the determinants was built up from the time groups principally.

When the work was practically complete cyphering method (4) was introduced and the fact that the original figures of the book were not in our possession prevented any possibility of decypherment. The key changed daily and an average of well under 30 messages were available in any one day. It was reckoned that to have a completer decypherment of any key it was necessary to guess the numerical equivalent of 219 symbols.

It may here be marked that when a small amount of material only is available, as was always the case in the Adriatic, it is essential for the determing of the exact sense of such groups as those taken from a phrase book or those constructed in the tabular principle that the decypherer should have every available assistance both from direction finding wireless and from aeroplane or submarine sightings. The known case should then be applied to the effect and by careful comparison exactitude can be attained. This really concerns only the building up of a book underneath an unsolved cypher, as was done in this case, and when no system or method had been used in its construction.

The fact that we possessed an ancient code book was of undoubted aim though it will be seen that , except in general principle, KODDREI was a very different book to that in our hands. But from the old book we knew the kind of thing to expect and the main vocabulary (as stated at the beginning of the document) remained pretty much the same.

On July 1^st 1918 KODVIER came into force. The copy that we possess shows it to be a re-hash of KODEINS but the alterations are sukzessive. All system in the numbering of the pages disappears and necessitates the transmutation of the 10 letter group first into five figure groups and the 3 figures of the page number subsequently into the paginant before the meaning can be turned up.

The tabular matter described in KODEINS occurs only once in the book but the numbering of words in these pages is in different order to those on the other pages. The same applies to the section dealing with urgent signals as well as the auxiliary table. This would undoubtedly have rendered the building up of the book far more difficult than in KODDREI when the array in all pages was the same. At the same time although only some 250 signals cyphered in the “46” method had been received in this code up to the time of the armistice and these signals were mainly sightings of enemy aeroplanes good progress had already been made.

The book however was constructed principally for use with the 244 method and would have been an extremely difficult proposition.

On October 1^st 1918 cyphering method (5) for the use with KODVIER came into force.

 

In discussing the merits and demerits of any code book or system of cyphering it is difficult not to become involved in the intricacies of wireless procedure, if the book was so employed. So much can often be learned from operator´s errors that it is impossible to ignore them but it is not felt that this is the place for such matters nor is it intended to launch out into arguments on the general principles of code building or cypher making.

In dealing with the Austrian methods it must be kept clearly in mind that wireless was not used under this system of fleet signalling to anything like the extent that it was in either the English or German Navies. Firstly the number of units was far smaller, secondly the whole naval situation in the Adriatic was governed by totally different conditions; such as the existence of the islands screen in front of the Austrian ports, protecting deep water channel behind which traffic could thus be guided; the difficulty of laying mine fields in the deep and very clear water; the absence of minelaying submarines in the Mediterranean on the Entente side and the lack of mines, all of which tended to make navigation simple and the use of elaborate out post and mine sweeping organisation unnecessary; the proximity to land of all operations and the consequent employment of optical signalling. The Austrian had installed a system of land communication via shore signalling stations so that they passed all orders by land line to their various bases, using wireless only as an adjunct. These conditions resulted in an average of rather under then over thirty signals a day being passed by wireless, as against the German average of a normal day, 5 times that number, and the “story” being frequently disjointed. Moreover the absence of incident or “liveliness” combined with the absence of routine rendered the problem quite other than that of the North Sea.

There can be no doubt that the system of turning figure groups into letter groups is satisfactory from 2 points of view firstly the familiarity which operators obtain with the words used, regardless of their meaning or key; secondly if used carefully as in method 4, it sufficiently cloathes the underlying figures as to prevent their reconstruction, always assuming that the book is not in enemy´s hands.

In order to show how great variety of group can be obtained by method 4 one or two examples are given:

Assume for the moment thus that RY=4, KO=5

In the first place JURY=91, AKOF=01, TUPF=92

In the second place AKOF=23, MEXY=24

 

The group       12349  is written        49123  and cyphered RYJURYAKOF

                        12350                         50123                         KOAKOFAKOF

                        12449                         49124                         RYJURYMEXY

                        22349                         49223                         RYTUPFAKOF

 

In the adjacent groups RYJURYAKOF and KOAKOFAKOF it will be seen that a very large number of recurrences would be necessary of each word before it would be realised that they were adjacent groups, where it might be easily assumed that RYJURYAKOF and RYJURYMEXY held a similarity of position. Or again assuming that the point had been reached (as in practice it was) when the inversion of the group before cyphering was adopted, it was difficult to locate the relative positions of, say, RYJURYAKOF and RYTUPFAKOF.

Apply the above system to a figure code arbitrarily compiled and it will be seen at once that it has no advantage spare that of operating facility. It is only useful where the code compiler has been compelled to adhere to the system of using the same book for coding and decoding.

The fact remains that when the basic code book any system the above method conceals the system and with a constant change of key so as to prevent the accumulation of any large amount of material, the decypherer is placed in the same position as if the code were arbitrarily compiled. Should the basic book however fall into the decypherer´s hands it is probably safe to assume that with a certain amount of practice the cypher could be solved.

At the same time a warning must be given that it is unfair to assume in pure theoretical cryptography any previous knowledge of the contents of a message and that the decyphering of Austrian codes was always found to necessitate a largish amount of material, even the advantageous position when the contents could be deduced from other sources, and that it always was a laborious task.

Lastly the cypher maker had in his endeavours to overcome the inherent weakness of a single code and decode involved the decoder in a more complicated manoeuvre, these being first the transmutation into figures and secondly the changing of figures into pagination. The only observation that remains to be made in this tread is that in spite of the above Austrian signalling and coding was uniformly good and comparatively rapid.

Considering the unfavourable atmospheric conditions prevailing for over half the year in the Adriatic remarkably few cheeks and repeats were necessary. Only once in the whole history of code work in the Adriatic was a signal sent first in one key and subsequently in another. It is interesting to note that all coding and decoding was done by petty officers.”

It has to be added that the coding and decoding was important part of the work of the radio officers, who had their battle station in the radio room. Therefore the good radio work was a result of the teamwork between officers, petty officers and signalling rates (“Telegraphisten”).

 

Pic.: Radio officers in the radio room of the battleship VIRIBUS UNITIS or TEGETTHOFF, equipped with a TELEFUNKEN 5 TVZ radio station. In the back to the right Linienschiffsleutnant Richard Kubin, Linienschiffsleutnant Franz Leist is sitting next to the receiver.

 

ADM 137/4684: “As to the code books themselves it is by now a recognised axiom that no numerical-alphabetical code is sound. All the Austrian books suffer from this default, though KODVIER provides a number of complications of the principle. All their books were in appearance cumbersome though when in use, with the exception of KODVIER, were found easy enough to handle once the decoder was familiar with the construction. Granted the above defect there can be no question that considerable ingenuity was shown in the compilation, such as the 4 different ways of using each place name and each unit of the fleet, the tabular arrangement of the enemy sighting tables, speeds, distances etc., while the phrase book was in constant use. The method of using the square chart was peculiarly elaborate but it was so seldom extracted that one is tempted to assume that the users of the book found it complicated (complete instructions for its use will be found in the original copy of the first book at the end. Reservat Dienst Buch No. 54 Beilage F).

The Austrian always scored heavily by having no routine signals. It has always been a question as to how far this was due to very careful instructions of signalling officers, how far to their lack of stereotyped phraseology and how far to complete lack of fleet organisation as under use in the North.

The fact remains that practically the only two things that could be laid hold of when keys changed were firstly a message ordering lights and secondly the W/T practice orders. Neither type of message occurred with any regularity.

In solving the submarine keys it must be remembered that the signals were made principally by German boats and with their usual charity.

It would seem as if the Germans were naturally incapable of coding messages without giving the decypherer that guiding point for which he thoroughly  prays.”

 

How some of the Austrian-Hungarian code books came into British possession after the war is told in the reports[46] of Lieutenant William Heywood Haslam.

He reported: “The Austro-Italian Armistice occurred a few days prior to the German Armistice in November 1918. As a Lt. RNVR I had been for several years Liaison Officers with the Italian Intelligence in Rome. On the Italian Armistice being declared my Italian Chief invited me to accompany the impending Naval Expedition to Dalmatia. (…)

The only real excitement was the Naval base of Pola; (…)

In Pola the Mutineers had played havoc with the ships. I came across a pile of cyphers which I put in a sack to the British Admiralty. The reason being that in Rome I had had with me expert decipherers, seconded from Room 40 in early 1918. They had failed to crack Austrian Naval Codes. For this there were two probable reasons:-

(1) The Austrians were better cryptographers than the Germans

(2) Naval happenings in the Adriatic followed silence by the enemy

Indeed the sinking of the Battleship “SZENT ISTVÁN” was followed by dead silence. In similar circumstances the Germans would have given Room 40 a bonanza !”

 

Pic.: Battleship SZENT ISTVÁN sinking on 10 June 1918

 

Evaluation of Allied results in Decoding and Decyphering of the radio communication of the k.u.k. Kriegsmarine[47]

 

France and Italy[48] monitored the Austrian-Hungarian radio traffic from the beginning of the War in August 1914, Great Britain engaged his specialists in decyphering to the k.u.k. Kriegsmarine Codes only in August 1917.

According to General Odoardo Marchetti recorded enemy radio messages were collected in the “Ufficio Informationi”, but there was not much progress in decyphering as no Austrian-Hungarian code book was “obtained” before the war. This changed when the code book of UC 12 came into possession of Italy in April 1916, a copy of which was forwarded to the French and the British. Until May 1916, when there was another change in the Austrian-Hungarian Naval Codes Italy and France could read the code KOD (for submarines) and in Italy the “Riparto Crittigrafico” under Captain (Army) Luigi Sacco was formed to deal with enemy codes.

Alongside the Italian coast a net of direction finding stations was in operation and by 1917 good results were obtained in determining the position of enemy units, when they used their radio stations. This was of great importance for locating German and Austrian-Hungarian submarines.

The k.u.k. Kriegsmarine was aware of the allied direction finding network and from mid 1916 radio silence was ordered for most actions in the Adriatic. The submarines, which were at sea for days or weeks, could not keep radio silence, when they asked for information when entering the home port, e.g. for new mine fields or for identification for the harbour defence vessels.

The Austrian-Hungarian Naval Code books from 1916 and the results of the allied decypherers according to the British ID 25:

 

KODEINS, valid from 4 September 1916:

No work to achieve a solution was done.

 

KODZWEI, valid from 1 May 1917:

Partly solved by the French, but only in Autumn 1917 after KODDREI was already in use.

 

KODDREI, valid from 14 October 1917:

Solved by the French and British in Autumn 1917, when the new cyphering method (4) came into force in January 1918 no progress in decoding was made

 

KODVIER, valid from 1 July 1918:

Only some progress was made in October 1918 after the simplified cyphering method (5) was introduced.

 

KOD (for the use with submarines):

This code was solved because of the busy radio traffic of the German and Austrian-Hungarian submarines and the code book found onboard UC 12 in April 1916.

 

It can be said that against the Austrian-Hungarian navy the importance of radio direction finding was higher in warfare than the decryption of messages, which came usually too late to influence the rapid actions in the Adriatic.

 

Österreichisches Staatsarchiv, Kriegsarchiv:

Files of the Marine-Sektion

            Präsidialkanzlei (PK)

            Operationskanzlei (OK)

            II. Geschäftsgruppe: Technische Akten

Nachlässe:

Peter Freiherr von Handel-Mazzetti / B 1209

Eugen Randich / B 1461 / C 1461

Maximilian Ronge / B 126

August Urbanski von Ostrymiecz / B 58

 

Imperial War Museum, London

Papers of Lt. W.H. HASLAN, RNVR, OBE, The Adriatic (November 1918), IWM, Department of Documents 71/134/1

Public Record Office, London

Different ADM-Files, especially:

ADM 137/780, 781, 496, 713, 714, 715: Reports of Proceedings of the Rear-Admiral Commanding British Adriatic Squadron, 18.5.1915 till 29.11.1918

ADM 137/4455: Anleitung zum Chiffrieren, Vorschrift für das Verziffern, das Schlüsseln und Umbilden (2. Auflage), Reserviertes Dienstbuch Nr. 54 (Aa), K.u.k. Flottenkommando, Res Nr. 225/Ra von 1916, Wien 1916

ADM 137 / 4461 Coding Tables (Austrian document)

ADM 137 / 4684 Enemy Wireless Stations, 25 October 1918

Austrian Naval Cyphers (Handschriftlich) 1919?

 

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