He showed that the halting problem was undecidable.
This man and Donald Bayley created a secure voice communications machine called "Delilah". The Chinese Room Experiment was developed by John Searle in response to one of this man's namesake tests. He showed that the halting problem was undecidable. He devised a bombe with Gordon Welchman that found the settings of an Enigma machine. One of this man's eponymous machines which can perform any computing task is his namesake "complete." Name this man, whose eponymous test is used to determine if a machine can exhibit behavior indistinguishable from that of a human.
This man and Donald Bayley created a secure voice communications machine called "Delilah".
Alan Mathison {Turing}