Every cipher has a "key"—information used to decipher a message. Some ciphers have simple keys, others, complex ones. The key for a cipher used by Augustus Caesar, some 2,000 years ago ...
But we were impressed with [SirDan’s] Morse code decoder built with the graphical MakeCode. Granted, it is reading 5 element groups from a button on the BBC micro:bit and not worrying about ...