CryptographY

CryptographY (from the Greek kryptós and gráphein, "to write") is the study of the principles and techniques by which information can be concealed in ciphers and later revealed by legitimate users employing the secret key, but in which it is either impossible or computationally infeasible for an unauthorized person to do so.

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See also:

:* CryptologY
:* CryptanalysiS