Encryption is the process of transforming information using an algorithm to make it unreadable to anyone except those possessing special knowledge, usually referred to as a key. Encryption is generally used to safeguard sensitive information from unauthorized access.
Janus used very complex encryption to safeguard the information hidden in his secret lab. (SGA: "First Contact")
Anubis used a complex system of deciphering his coding into Ancient language. (SG1: "Fallen")