In 1931, the Poles unexpectedly received important and timely help from the French special services: a traitor appeared in Germany among the employees of the Ministry of Defense, who approached the French government with a proposal to sell secret documents. It was Hans-Thilo Schmidt, and among his "goods" was the manual for the German encryption machine "Enigma". Schmidt entered the history of intelligence under the codenames "Asche" or "Source D" and ended his life quite naturally - in 1943 in the dungeons of the Gestapo.
Hans-Thilo Schmidt. Source: wikipedia.ru
However, until the moment of his arrest, the traitor to the ideals of the Third Reich actively collaborated with the French and, in particular, gave them 38 cipher books for the Enigma. And if the Germans had not occupied France and had not found evidence of the presence of a "mole" in the archives of enemy intelligence, then Schmidt would have remained undetected. The Polish cryptanalyst Marian Rezhevsky spoke very eloquently about the importance of the agent: “Ashe's documents were like manna from heaven, and all doors immediately opened.” But let's return to 1931, where representatives of the Second Bureau (French intelligence) agent Rudolph Lemoine and the head of the encryption department Gustave Bertrand hit the hands with Schmidt, and a deal for 10 thousand marks took place.
Rudolph Lemoine. Source: wikipedia.ru
French cryptographers got acquainted with the most valuable information on the Enigma machine, understood how it encrypts messages, but they could not decode its messages on their own. The frustrated specialists of the Second Bureau turned to the British, but they, too, were powerless. Having received the appropriate powers, Gustave Bertrand passed the information to the Polish cryptographers, but they only concluded that the Germans had adapted the commercial "Enigma" for the army's needs. Even the European leaders of cryptography, the Poles, could not provide any special breakthrough in decryption. As a result, the agents of the Second Bureau began to harass the old acquaintance of Hans-Thilo Schmidt, who had obviously already spent the fee for the deal. As a result, in May and September 1932, Schmidt handed over new key Enigma installations to France.
The contacts between the Poles and the French in the field of decryption were very peculiar: the specialists from the Second Bureau could not independently figure out the codes and went to bow to the Poles. And the representatives of Poland willingly used the intelligence of a foreign country and in every possible way assured the French that the issue would be resolved soon. In fact, Poland was very reluctant to share the results of its work in the direction of "Enigma". It remained a secret for the Allies that a model of a German encryption machine had already been built in this country for a full-fledged test of decryption techniques. Moreover, by 1933 Poles could actually read the Enigma ciphers. And here again it was not without intelligence work.
In the 1930s, Polish secret services discovered a plant for the production of German encryption machines in southeastern Germany. Since 1933, a group of underground workers has been actively involved in the process of studying this secret plant and the results have been very valuable for cryptanalysis. But all this collapsed with the advent of 1938, when the Germans changed the procedure for using key settings, introducing, in particular, one-time key settings that form unique initial positions of the disks that change with each communication session. Since this year, the Poles have had noticeable difficulties in deciphering.
The problem had to be somehow solved, and Marian Rezhevsky came to AVA with the firm intention of making an "Anti-Enigma" capable of "hacking" the German superscript. The device was named "Bomb" and consisted of six interconnected "Enigmas". The principle was simple in general terms: the message was decrypted by enumerating the initial positions of the disks.
Anglo-Polish models of the "Bomb" car. Source: fofoi.ru
The “Bomb” did this in approximately two hours, while making the sound of a ticking clock, for which it got its name. In order to speed up the decryption, the Poles launched several "Bombs" in parallel. It is noteworthy that this whole story was beyond the knowledge of the British and French, who continued to share with Poland the results of their intelligence work with Schmidt. The Germans delivered difficulties to the Bomb in 1938 by installing five disks at once, of which only three participated in the key installation. The Poles did not have enough intelligence to hack such material, and in the summer of 1939 they turned to the British and French for help. Two days in July of the same year in Warsaw, the English cryptanalyst Dilly Knox, the director of the English Government Cryptographic School Alistair Denniston, the head of the encryption department of the Second Bureau Gustave Bertrand and his colleague Henry Brackeni came to their senses from Polish selfishness on the Enigma issue.
Bombs at the Bletchley Park Museum. Source: fofoi.ru
In those days, the Poles passed on one copy of scramblers to England and France, as well as a genuine innovation of those times - punched cards with detailed instructions on how to use and make them. When the Germans occupied Poland, the local encryption bureau fled to France via Romania, destroying all Enigmas and Bombs beforehand. They did it masterfully, the Nazis did not even suspect the very fact of the Polish deciphering work. From that moment on, joint Franco-Polish work began on the problem of German codes - until April 1940, 15 thousand orders, directives and other enemy messages were read. When it was France's turn to become part of the Third Reich, the work naturally had to be curtailed, but it was not possible to cover up the tracks so carefully, in Polish, which allowed the Gestapo to eventually get on the trail of Hans-Thilo Schmidt.
The British were the most successful in disposing of the Polish heritage, organizing a large-scale operation "Ultra" on their territory, gathering their best linguists, cryptographers and mathematicians in the town of Bletchley Park in Buckinghamshire. A distinctive aspect of Ultra was the unique secrecy regime with which the British surrounded Bletchley Park. The former head of the British Security Service F. Winterbotham once said in this regard: any actions that could arouse suspicion in the enemy, or confirm his fears that the allied command knew his plans … Under certain conditions it may be tempting to strike a blow that will reveal the secret … ".
