Who said A riddle wrapped in a mysteryinside an enigma?

The famous quote "A riddle wrapped in a mystery inside an enigma" is attributed to Winston Churchill, although there is no definitive proof that he actually uttered it.

The quote was first recorded in a 1970 biography of Churchill, and while it's a commonly accepted quote, it's unclear if he truly said it or if it was just a clever summary of Churchill's thoughts on a complex issue.