Cryptography, or cryptology (from Ancient Greek: κρυπτός, romanized: kryptós "hidden, secret"; and γράφειν graphein, "to write", or -λογία -logia, "study", respectively [1]), is the practice and study of techniques for secure communication in the presence of adversarial behavior. [2]
Cryptography, as defined in the introduction to this article, is the science of transforming information into a form that is impossible or infeasible to duplicate or undo without knowledge of a secret key.