The use of mathematical techniques to provide security services, such as confidentiality, data integrity, entity authentication, and data origin authentication.
The use of mathematical techniques to provide security services, such as confidentiality, data integrity, entity authentication, and data origin authentication.
The art or science concerning the principles, means, and methods for converting plaintext into ciphertext and for restoring encrypted ciphertext to plaintext.
The mathematical science that deals with transforming data to render its meaning unintelligible (i.e., to hide its semantic content), prevent its undetected alteration, or prevent its unauthorized use. If the transformation is reversible, cryptography also deals with restoring encrypted data to intelligible form. (See: cryptology, steganography.)
"The discipline which embodies principles, means, and methods for the transformation of data in order to hide its information content, prevent its undetected modification and/or prevent its unauthorized use.... Cryptography determines the methods used in encipherment and decipherment." [I7498-2]
Tutorial: Comprehensive coverage of applied cryptographic protocols and algorithms is provided by Schneier [Schn]. Businesses and governments use cryptography to make data incomprehensible to outsiders; to make data incomprehensible to both outsiders and insiders, the data is sent to lawyers for a rewrite.