Homonym: cipher (Code)
A cipher is a method used to encrypt or encode information, making it unreadable to anyone who does not have the key to decode it. Ciphers can transform plain text into a scrambled format, ensuring that only authorized individuals can access the original message. They are commonly used in various fields, including computer security and military communications.
There are many types of ciphers, such as substitution ciphers, where letters are replaced with other letters, and transposition ciphers, which rearrange the letters in a message. Famous historical examples include the Caesar cipher, named after Julius Caesar, who used it to protect military messages.