cryp·tog·ra·phy /krɪpˈtɑgrəfi/
  密碼使用法,密碼
  cryptography
  密碼術
  cryptography
  密碼學
  Cryp·tog·ra·phy n.
  1. The act or art of writing in code or secret characters; also, secret characters, codes or ciphers, or messages written in a secret code.
  ◄ ►
  cryptography
       n 1: the science of analyzing and deciphering codes and ciphers
            and cryptograms [syn: cryptanalysis, cryptanalytics,
             cryptology]
       2: act of writing in code or cipher [syn: coding, secret
          writing]