1. The art or science concerning the principles, means, and methods for rendering plain information unintelligible, and for restoring encrypted information to intelligible form. 2. The branch of cryptology that treats of the principles, means, and methods of designing and using cryptosystems. 3. The discipline which embodies principles, means, and the methods for the transformation of data in order to hide its information content, prevent its undetected modification and/or prevent its unauthorized use. Note: Cryptography determines the methods used in encipherment and decipherment. An attack on a cryptographic principle, means, or methods is cryptanalysis.