The Common Biometric Exchange Formats Framework (CBEFF) describes a set of data elements necessary to support biometric technologies in a common way. These data elements can be placed in a single file used to exchange biometric information between different system components or between systems. The result promotes interoperability of biometric-based application programs and systems developed by different vendors by allowing biometric data interchange. This specification is a revised (and augmented) version of the original CBEFF, the Common Biometric Exchange File Format, published as NISTIR 6529. In addition to the name change, which reflects more accurately the scope of the specification, NISTIR 6529-A incorporates new features such as a CBEFF nested structure in order to support multiple biometric data types (e.g., finger, face and voice) and/or multiple biometric data blocks of the same biometric type (e.g., finger biometric data blocks from more than one finger) within a CBEFF data structure, a Biometric Feature to further define the type of biometric data being placed in the file, a Validity Period for that data, an expanded definition of the Creator field which now specifies a Product Identifier, and Index Field associated with a specific instance of biometric reference data, a Challenge-Response field and a Payload field. NISTIR 6529-A also defines two new CBEFF Formats, biometric data objects for use within smart cards and other tokens and a simple root header for use in domains where more than one Patron Format, simple or nested, may be encountered. CBEFF provides forward compatibility accommodating for technology improvements and allows for new formats to be created. CBEFF implementations simplify integration of software and hardware provided by different vendors. CBEFF’s initial conceptual definition was achieved through a series of three Workshops cosponsored by the National Institute of Standards and Technology and the Biometric Consortium. A Technical Development Team, formed as a result of these Workshops, developed the original version of CBEFF. This version is based on the specification developed by the CBEFF team under the Biometrics Interoperability, Performance, and Assurance Working Group (NIST/BC WG) co-sponsored by NIST and the Biometric Consortium. It also embodies features recommended by many biometric experts to clarify CBEFF’s purpose and functions, and to facilitate wider implementation of CBEFF compliant biometric solutions while maintaining attributes of the earlier version required by implementations that are already in conformance with CBEFF.