Polish Cipher Bureau had been also using leading mathematicians for breaking Soviet ciphers before WW2… During Polish-Soviet War 1920 Polish HQ had such a comp

Polish Cipher Bureau had been also using leading mathematicians for breaking Soviet ciphers before WW2… During Polish-Soviet War 1920 Polish HQ had such a complete knowledge of Soviet movements that they had to stage a deception. Polish cavalary division had been sent behind enemy lines to attack Soviet divisional HQ taking all code books and machines to give Soviets credible explanation for Polish ability to read Soviet ciphers. https://en.wikipedia.org/wiki/Cipher_Bureau_(Poland) https://en.wikipedia.org/wiki/Cipher_Bureau_(Poland)