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Authenticated Encryption (AE) is a term used to describe encryption systems which simultaneously protect confidentiality and authenticity (integrity) of communications. These goals have long been studied, but they have only recently enjoyed a high level of interest from cryptographers due to the complexity of implementing systems for privacy and authentication separately in a single application. “Cipher†redirects here. ...
Confidentiality has been defined by the International Organization for Standardization (ISO) as ensuring that information is accessible only to those authorized to have access and is one of the cornerstones of Information security. ...
Look up authenticity, authentic in Wiktionary, the free dictionary. ...
Pre-19th century Leone Battista Alberti, polymath/universal genius, inventor of polyalphabetic substitution (see frequency analysis for the significance of this -- missed by most for a long time and dumbed down in the Vigenère cipher), and what may have been the first mechanical encryption aid. ...
Authentication (from Greek αυθεντικός; real or genuine, from authentes; author) is the act of establishing or confirming something (or someone) as authentic, that is, that claims made by or about the thing are true. ...
In addition to protecting message integrity and confidentiality, authenticated encryption can provide plaintext awareness and security against chosen ciphertext attack. In these attacks, an adversary attempts to gain an advantage against a cryptosystem (e.g., information about the secret decryption key) by submitting carefully chosen ciphertexts to some "decryption oracle" and analyzing the decrypted results. Authenticated encryption schemes can recognize improperly-constructed ciphertexts and refuse to decrypt them. This in turn prevents the attacker from requesting the decryption of any ciphertext unless he generated it correctly using the encryption algorithm, which would imply that he already knows the plaintext. Implemented correctly, this removes the usefulness of the decryption oracle, by preventing an attacker from gaining useful information that he does not already possess. Plaintext-awareness is a notion of security for public-key encryption. ...
A chosen ciphertext attack is an attack on a cryptosystem in which the cryptanalyst chooses ciphertext and causes it to be decrypted with an unknown key. ...
Many specialized authenticated encryption modes have been developed for use with symmetric block ciphers. However, authenticated encryption can be generically constructed by combining an encryption scheme and a Message Authentication Code (MAC), provided that the encryption scheme is semantically secure under chosen plaintext attack and the MAC function is unforgeable under chosen message attack. Bellare and Namprempre (2000) analyzed three compositions of these primitives, and demonstrated that encrypting a message and subsequently applying a MAC to the ciphertext implies security against adaptive chosen ciphertext attack, provided that both functions meet the required properties. Encryption Decryption In cryptography, a block cipher is a symmetric key cipher which operates on fixed-length groups of bits, termed blocks, with an unvarying transformation. ...
A cryptographic message authentication code (MAC) is a short piece of information used to authenticate a message. ...
Semantic security is a widely-used definition for security in an asymmetric key encryption algorithm. ...
A chosen plaintext attack is any form of cryptanalysis which presumes that the attacker has the capability to choose arbitrary plaintexts to be encrypted and obtain the corresponding ciphertexts. ...
An adaptive chosen ciphertext attack is an interactive form of chosen ciphertext attack in which an attacker sends a number of ciphertexts to be decrypted, then uses the results of these decryptions to select subsequent ciphertexts. ...
See also CCM mode (Counter with CBC-MAC) is a mode of operation for cryptographic block ciphers. ...
In cryptography, CWC Mode (Carter-Wegman + CTR mode) is an AEAD block cipher mode of operation designed by Tadayoshi Kohno, John Viega and Doug Whiting. ...
OCB mode (Offset Codebook Mode) is a mode of operation for cryptographic block ciphers. ...
EAX mode is a mode of operation for cryptographic block ciphers. ...
GCM mode (Galois/Counter Mode) is a mode of operation for symmetric key cryptographic block ciphers. ...
References - M. Bellare and C. Namprempre, Authenticated Encryption: Relations among notions and analysis of the generic composition paradigm. Extended abstract in Advances in Cryptology - Asiacrypt 2000 Proceedings, Lecture Notes in Computer Science Vol. 1976, T. Okamoto ed, Springer-Verlag, 2000.
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