In cryptology, a code is a method used to transform a message into an obscured form so it cannot be understood. Special information or a key is required to read the original message. The usual method is to use a codebook with a list of common phrases or words matched with a codeword. Encoded messages are sometimes termed codetext, while the original message is usually referred to as plaintext.

In cryptology, a code is a method used to transform a message into an obscured form so it cannot be understood. Special information or a key is required to read the original message. The usual method is to use a codebook with a list of common phrases or words matched with a codeword. Encoded messages are sometimes termed codetext, while the original message is usually referred to as plaintext.