Original sentence: Critics argue that, in the movie the fictitious traitor turns out to be Polish, while only slight mention is made of the contributions of prewar Polish Cipher Bureau cryptologists to Allied Enigma-decryption efforts, and that, historically, the only known traitor active at Bletchley Park, was British spy John Cairncross, who passed crucial secrets to the Soviet Union.It stars Dougray Scott and Kate Winslet and is based on a novel of the same title by Robert Harris (Enigma)
Edited sentence: (This is the standard reference on the Polish part in the Enigma-decryption saga.As a matter of fact, there was at least one traitor active at Bletchley Park, passing crucial secrets to the Soviet Union — the British spy, John Cairncross.In the movie the fictitious traitor turns out to be Polish, while only slight mention is made of the seminal contributions of prewar Polish Cipher Bureau cryptologists to Allied Enigma-decryption efforts.It stars Dougray Scott and Kate Winslet and is based on a novel of the same title by Robert Harris.Those contributions included the Poles' reconstruction of the Enigma machine and their design and construction of equipment such as:.Władysław Kozaczuk, Enigma:  How the German Machine Cipher Was Broken, and How It Was Read by the Allies in World War Two, edited and translated by Christopher Kasparek, Frederick, MD, University Publications of America, 1984.the cryptologic bomb.the cyclometer,.the perforated sheets, and