Commemorating the Battle of Warsaw
Jan Kowalewski (public domain)
The Japanese had no intention of permitting us to rest on our laurels, so from 1919 until the spring of 1920 they introduced eleven different encryption codes for their communications.
We learned that they had employed a Polish cipher expert to revise their code and cipher systems. It took all of our skill to break the new codes that this man produced … The Polish cryptographer seemed to specialize in army codes, for the Japanese Military Attaché's codes suddenly became more difficult than those of any other branch of the Japanese Government. This new system was elaborate and required ten different codes.” The Polish cipher expert mentioned by American cryptologist Herbert O. Yardley, founder and leader of the Black Chamber (American Cipher Bureau) was none other than Jan Kowalewski. For his help with training Japanese radio intelligence officers the Polish cryptographer was awarded the highest military award in Japan – the Order of the Rising Sun.
At this stage Kowalewski was already the holder of another medal, one closer to his heart, the Silver Cross of Virtuti Militari. He had been given this honour for aiding the Poles in their victory in the Polish-Soviet war during which his talents were put to good use. The path to his spectacular success started by accident when he offered to stand in for his colleague Lieutenant Sroka whose sister was about to get married. Sroka’s work was to assess and intercept Russian radio traffic.
While performing the duties of his absent friend, out of boredom, Kowalewski occupied his brain by breaking the intercepted codes. the fact that he was an engineer and polyglot who was familiar with the practicalities of Russian signal intelligence from his time in the imperial army, Kowalewski was well equipped to succeed in this activity His spectacular abilities activities caught the eye of the Polish chief-of-staff General Rozwadowski, who was incredibly pleased to be able to eavesdrop on Russian communication on a regular basis.
Kowalewski was put in charge of General Staff’s radio-intelligence department. To boost the probability of the department’s success Kowalewski decided to take an interdisciplinary approach to human resources and to recruit mathematicians alongside linguists. He worked with many professors from Warsaw and Lviv’s Universities –including the founders of the Polish School of Mathematics.
The new approach to codebreaking, combining a knowledge of Russian language with logical mathematical thinking, quickly brought results and allowed the team to read operational orders from the Russian Front. Although the Soviets painstakingly changed the keys Kowalewski took personal pleasure in breaking them.
Thanks to constant surveillance of the enemy, members of the Polish General Staff were well aware that successfully dealing with Deniikin meant that the Bolsheviks would turn their attention to the western border next. A large part of the Polish success in stopping the Soviet offensive during the famous Battle of Vistula should be attributed to Kowalewski’s farsightedness and his extraordinary vision for organising the works of the radio-intelligence department.
A Russian telegram, countersigned by Stalin, and decoded by Jan Kowalewski during the Polish-Soviet War 1920. Archive of Piłsudski Institute of London