January 9, 1939: After a lunch at restaurant Drouant in Paris, in the office of the French Cryptology Services, Polish Lt Colonel Langer and Major Ciezki reveal for the first time to the British Commander Denniston and MM Knox and Foss, invited by the French Major Gustave Bertrand, the advance they have reached in deciphering the messages crypted by Enigma machines. The work of the genial Polish mathematician Marian Rejewski’s had been made possible by the essential documents on key tuning supplied by the French spy Hans Tilo Schmidt. The Polish team however do not supply technical details to their French and English counterparts.
Paillole, Paul: Notre espion chez Hitler p 163 & p 260/270