Solve This Riddle in Honor of Alan Turing's Birthday [UPDATE: Answer Revealed]

23 JUN 2017

In honor of Alan Turing’s birthday, inventor of the Turing machine and famous code breaker of the Second World War, see if you can crack this code:

BZ R UNIACEM VY XRGMPZXX KW OK BHWIYRBVCM, VZ VUEVBZ TFJW OK BHKMYRBAVVG.

The answer is: IF A MACHINE IS EXPECTED TO BE INFALLIBLE, IT CANNOT ALSO BE INTELLIGENT.

Here’s how we solved it: This is a Vigènere Cipher, with the key of “TURING.” The answer originates from a quote by Turing in 1947.

We decoded the message using the following method:

Convert every letter a-z into a number 0-25, and for each letter at position x in the code (excluding spaces and punctuation):
Message( x ) = Mod( Code( x ) – Key( Mod( x, Length( Key ) ) ), 26),
where Code( x ) corresponds to the xth letter in the Code, etc.