Crack a cipher is a term used to describe the process of decoding a coded message. It involves deciphering a code or cipher, which is a set of instructions for transforming a message into an unreadable form. This process can be done manually or with the help of computer programs. DECODE is a six letter word that is used to describe the process of cracking a cipher. It involves taking a coded message and using a set of instructions to decipher it and make it readable.