BioAPI

BioAPI (Biometric Application Programming Interface)is a key part of the International Standards that support systems that perform biometric enrollment and verification (or identification). It defines interfaces between modules that enable software from multiple vendors to be integrated together to provide a biometrics application within a system, or between one or more systems using a defined Biometric Interworking Protocol (BIP) - see below.

Biometrics (measurements of physical characteristics of a person) are increasingly being used to provide verification of the identity of an individual, once they have been enrolled (one or more of their physical characteristics has been measured).

Computer systems that perform biometric enrollment, verification, or identification are becoming increasingly used. The BioAPI specification enables such systems to be produced by the integration of modules from multiple independent vendors.

Origins

The BioAPI specification is one of a set of International Standardsproduced jointly by the International Organisation for Standardisation (ISO) and the
InternationalElectrotechnical Commission (IEC) under their Joint Technical Committee 1 (JTC1), SubcommitteeSC37 Biometrics.

The Standard was based on some early work done in the United States ofAmerica and by the [http://www.bioapi.org/ BioAPI Consortium] which was called BioAPI 1.0 and BioAPI 1.1, but these specifications wereheavily revised to correct bugs and to provide enhancements when the workwas introduced to ISO/IEC. The first international versionwas therefore called BioAPI 2.0. A subsequent international version of BioAPIcontaining extensions of the user interface-related features and otherenhancements produced a BioApi 2.1. Further enhancements to BioAPI areexpected.

BioAPI 2.0 is specified in ISO/IEC 19784-1 and was first published on1 May 2006.

What and why?

The purpose of the BioAPI specification is to define an architectureand all necessary interfaces (using C programming languagespecifications) to allow biometric applications (perhaps distributedacross a network) to be integrated from modules provided by differentvendors.

The ability for system integrators to produce complete systems usingcomponents from multiple vendors is essential in the rapidly changingtechnology of biometrics. It gives flexibility in the provision ofmodules, avoids vendor lock-in, provides a degree of future-proofing asthe best available biometrics technologies change.

The modules being integrated may be software components containingcapture devices, such as fingerprint readers, cameras for face recognition, irisscanners, signature recognition devices, vascular imaging systems, etc.

They can also be modules that provide support for imageprocessing of biometric data, feature extraction (a form of compressionthat is specific to a given biometric technology and allows directmatching of the compressed formats - for example, the relative distanceson the face of eyes, nose, mouth, or the number of ridges betweenidentifiable ridge endings or ridge bifurcations).

In addition, modules that provide archiving and retrieval of biometricrecords to support matching or searching for a match are also arecognised part of the BioAPI architecture.

Applications can be concerned with personal identification (forexample for credit cards), or with more specific areas such as identitycard verification, checks for duplicate enrollment, passports, or physicalaccess control in a commercial environment or for airport employees ormerchant seamen wishing to go on-shore at their arrival port.

Whilst today a system is commonly built using a single device for asingle application, it is likely that in the long term many suchapplications will interact (securely, and via a network) with a commonset of trusted devices (with various security policies and certificates).

It is also expected that future biometrics applications will usemultiple biometric modalities (for example, fingerprint, iris, and face),both to improve the accuracy of identification and to cope with people that aremissing a finger, or have disability problems that prevent use of iris orface recognition.

BioAPI supports all these use cases.

The basic architecture

The basic architecture of BioAPI 2.0 is illustrated in the figure atthe top of this page. There are multiple possible (independent)"biometric applications" thatinteract with a "BioAPI Framework", which in turn routes theirmessages to "Biometric Service Providers (BSPs)" that support thevarious biometric capture devices, imageenhancement modules, feature extraction, matching, searching, etc.

A later extension of the architecture introduces the concept of a"Biometric Function Provider (BFP)" and defines further lower-levelinterfaces between a BFP and a controlling BSP. This minimises theamount of software that a biometric device vendor needs todevelop, allowing (other) software vendors to do most of the work ofproducing the BSP with an interface to the framework.

Procurement issues

The "BioAPI Framework" is the heart of BioAPI. Procurements ofbiometric systems need to consider the merits of basing theirinvitations-to-tender on systems conforming to the BioAPI Standard,which contain a BioAPI Framework module.

The importance of this Framework module is recognised bythe [http://www.bioapi.org/BioAPI2_0ReferenceImplementation.html BioAPI Consortium] , which identifies an implementation of this Frameworkfrom [http://www.biofoundry.com/products/bioapi20_RI.html | BioFoundry] .

Distributed systems

It might be uncommon to find multiple biometric applications andmultiple biometric devices on a single computer system, but the long-termaim of telebiometrics is to allowmultiple biometrics applications on multiple systems on the Internet tointerwork with multiple other systems that support biometrics devices.

BioAPI has already laid the foundations for this, with itsarchitecture.

Another ISO/IEC JTC1/SC37 Standard - BioAPI Interworking Protocol(BIP) - specifies an enhancement of the BioAPI Framework that essentiallymaps all API calls into network messages (defined using ASN.1
ASN.1) to provide a distributed BioAPI system.

BIP is also being progressed as a Recommendation in ITU-T asJoint text with ISO/IEC.

References

ISO/IEC 19784-1, "Information Technology – BioAPI – Biometric Application Programming Interface – Part 1: BioAPI Specification"

ISO/IEC 24708, "Information Technology — BioAPI Interworking Protocol (BIP)"