crypt(o)-

Concealed or secret.

Greek kruptos, hidden.

One set of words relates to the production of messages intended only to be understood by the intended recipient, or to methods for illicitly reading them. Text containing such a private message is a cryptogram and the process of creating it is encryption; the art of preparing or reading codes or ciphers is cryptography; the techniques of cracking codes or ciphers to discover messages are collectively called cryptanalysis.

The form also appears in the biological sciences. A cryptogam (Greek gamos, marriage) is a plant that reproduces by spores, so named because the means of reproduction were not obvious at the time; some organisms survive dry conditions through cryptobiosis, in which their metabolic activity becomes undetectably low; cryptozoology is the search for species of animal whose existence is disputed.

A third group has the idea of some membership, allegiance, or belief kept secret, as in crypto-communist, crypto-fascist, or crypto-semite.