Authenticated Encryption
A number of modes of operation have been designed to combine confidentiality and authentication in a single cryptographic primitive. Examples of such modes are XCBC, IACBC, IAPM, OCB, EAX, CWC, CCM, and GCM. Authenticated encryption modes are classified as single pass modes or double pass modes. Unfortunately for the cryptographic user community, many of the single pass authenticated encryption algorithms (such as OCB mode) are patent encumbered.
In addition, some modes also allow for the authentication of unencrypted associated data, and these are called AEAD (Authenticated-Encryption with Associated-Data) schemes. For example, EAX mode is a double pass AEAD scheme while OCB mode is single pass.
Read more about this topic: Block Cipher Modes Of Operation