In recent weeks I managed to decrypt a difficult cipher that, despite expert codebreakers' best efforts, had remained unsolved for 70 years. The code was created by the late Cambridge professor and scientist Robert Henry Thouless, who passed away in 1984. He created it as a "test of survival" to see if he could communicate with the living after his death. Thouless thought if he successfully transmitted cipher keywords to the living through spiritual mediums and the message was received, this would prove he had survived his death. In 2019, I was more interested in seeing whether computer speed, storage and networking capabilities had advanced enough to break a code that had outlived its maker.