Authenticated Encryption with Associated Data (AEAD) is a class of block cipher modes

Block cipher modes of operation

In cryptography, modes of operation is the procedure of enabling the repeated and secure use of a block cipher under a single key.A block cipher by itself allows encryption only of a single data block of the cipher's block length. When targeting a variable-length message, the data must first be...

 which encrypt (parts of) the message and authenticate the message simultaneously. Interest in these modes was sparked by the publication of Charanjit Jutla's IACBC and IAPM modes http://eprint.iacr.org/2000/039 in 2000. As of 2005 this is an active area of cryptographic research. Examples of such modes include OCB mode

OCB mode

OCB mode is a mode of operation for cryptographic block ciphers.-Encryption and authentication:It was designed to provide both authentication and privacy. It is essentially a scheme for integrating a Message Authentication Code into the operation of a block cipher...

, CCM mode

CCM mode

CCM mode is a mode of operation for cryptographic block ciphers. It is an authenticated encryption algorithm designed to provide both authentication and confidentiality. CCM mode is only defined for block ciphers with a block length of 128 bits...

, EAX mode

EAX mode

EAX mode is a mode of operation for cryptographic block ciphers. It is an Authenticated Encryption with Associated Data algorithm designed to simultaneously provide both authentication and privacy of the message with a two-pass scheme, one pass for achieving privacy and one for authenticity for...

, CWC mode

CWC mode

In cryptography, CWC Mode is an AEAD block cipher mode of operation that provides both encryption and built-in message integrity, similar to CCM and OCB modes. Designed by Tadayoshi Kohno, John Viega and Doug Whiting, NIST is CWC mode for standardization...

 and GCM mode.