In the Film Imitation Game, Commander Denniston has found news of a Soviet Spy working at Bletchley Park, which they've managed to track back to Hut 8, the room in which Alan Turing works, so he has the guards search Turing's desk, thinking that he is the spy, but they find nothing. When Turing asks what this is about:
Denniston hands Alan a TELEGRAM — it’s a LONG STRING OF LETTERS, running down the entire page.
ALAN TURING: This is a Beale Cypher. It’s encrypted with a key phrase, from a book or a poem or...
And then later in the film:
HUGH ALEXANDER: Denniston gave me the Beale Cypher. And guess what? I broke it. “Ask and it shall be given you; seek and ye shall find.” Matthew 7:7. That was the key. Far too simple for you. Pity Denniston disagrees.
Why do they refer to a Beale Cipher? The Beale Cipher or Beale Papers are a specific set of coded messages reportedly created by Thomas Beale.
While it is always possible, even likely, that both accomplished mathematicians would have heard of the Beale Papers, what they are referring to seems more like a Vigenere Cipher. This is definitely something that Alan and Hugh would know of and would be unlikely to use the incorrect name.
I know it's unlikely that anyone would know the 100% truth as to what was said at the time in real life so...
Is there a known reason they called it a Beale Cipher in the film? Was it a small joke or easter egg? Or is there a mysterious Cipher called a Beale Cipher I'm not aware of?