WikiPedia: CryptologY

CryptologY is a science concerned with communications in secure and usually secret form. It encompasses both CryptographY and CryptanalysiS.

The term CryptologY is derived from the GreeK kryptós, "hidden," and lógos, "word." Security obtains from legitimate users, the transmitter and the receiver, being able to transform information into a CipheR by virtue of a key--i.e., a piece of information known only to them. Although the CipheR is inscrutable and often unforgeable to anyone without this secret key, the authorized receiver can either decrypt the CipheR to recover the hidden information or verify that it was sent in all likelihood by someone possessing the key.

The most frequently confused, and misused, terms in the lexicon of CryptologY are CodE and CipheR. Even experts occasionally employ these terms as though they were synonymous.