SIST-TP CWA 16926-78:2023

SLOVENSKI STANDARD
SIST-TP CWA 16926-78:2023
01-april-2023
Specifikacija vmesnika razširitev za finančne storitve (XFS), izdaja 3.50 - 78. del:
Predlog vmesnika za razred biometričnih naprav - Referenca za programerje -
Prehod z različice 3.40 (CWA 16926:2020) na različico 3.50 (ta CWA)
Extensions for Financial Services (XFS) interface specification Release 3.50 - Part 78:
Biometrics Device Class Interface Proposal - Programmer's Reference - Migration from
Version 3.40 (CWA 16926:2020) to Version 3.50 (this CWA)
Ta slovenski standard je istoveten z: CWA 16926-78:2023
ICS:
35.200 Vmesniška in povezovalna Interface and interconnection
oprema equipment
35.240.15 Identifikacijske kartice. Čipne Identification cards. Chip
kartice. Biometrija cards. Biometrics
35.240.40 Uporabniške rešitve IT v IT applications in banking
bančništvu
SIST-TP CWA 16926-78:2023 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.

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SIST-TP CWA 16926-78:2023


CEN
CWA 16926-78

WORKSHOP
January 2023

AGREEMENT


ICS 35.240.40; 35.200; 35.240.15
English version


Extensions for Financial Services (XFS) interface
specification Release 3.50 - Part 78: Biometrics Device
Class Interface Proposal - Programmer's Reference -
Migration from Version 3.40 (CWA 16926:2020) to
Version 3.50 (this CWA)
This CEN Workshop Agreement has been drafted and approved by a Workshop of representatives of interested parties, the
constitution of which is indicated in the foreword of this Workshop Agreement.

The formal process followed by the Workshop in the development of this Workshop Agreement has been endorsed by the
National Members of CEN but neither the National Members of CEN nor the CEN-CENELEC Management Centre can be held
accountable for the technical content of this CEN Workshop Agreement or possible conflicts with standards or legislation.

This CEN Workshop Agreement can in no way be held as being an official standard developed by CEN and its Members.

This CEN Workshop Agreement is publicly available as a reference document from the CEN Members National Standard Bodies.

CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,
Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Republic of North
Macedonia, Romania, Serbia, Slovakia, Slovenia, Spain, Sweden, Switzerland, Türkiye and United Kingdom.



EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION

EUROPÄISCHES KOMITEE FÜR NORMUNG

CEN-CENELEC Management Centre: Rue de la Science 23, B-1040 Brussels
© 2023 CEN All rights of exploitation in any form and by any means reserved worldwide for CEN national Members.


Ref. No.:CWA 16926-78:2023 E

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Table of Contents
European Foreword . 4
1. Introduction . 7
1.1 Background to Release 3.50 . 7
1.2 XFS Service-Specific Programming . 7
2. Biometric Devices. 9
2.1 Enrollment . 9
2.2 Biometric Matching . 9
2.3 Biometric Device Types . 10
2.4 Biometric Data Security . 10
3. References . 11
4. Info Commands . 12
4.1 WFS_INF_BIO_STATUS . 12
4.2 WFS_INF_BIO_CAPABILITIES . 15
4.3 WFS_INF_BIO_STORAGE_INFO . 20
4.4 WFS_INF_BIO_KEY_INFO . 21
5. Execute Commands . 22
5.1 WFS_CMD_BIO_READ . 22
5.2 WFS_CMD_BIO_IMPORT . 25
5.3 WFS_CMD_BIO_MATCH . 26
5.4 WFS_CMD_BIO_SET_MATCH . 29
5.5 WFS_CMD_BIO_CLEAR . 30
5.6 WFS_CMD_BIO_RESET . 31
5.7 WFS_CMD_BIO_SET_DATA_PERSISTENCE . 32
5.8 WFS_CMD_BIO_SET_GUIDANCE_LIGHT . 33
5.9 WFS_CMD_BIO_POWER_SAVE_CONTROL . 35
5.10 WFS_CMD_BIO_SYNCHRONIZE_COMMAND . 36
6. Events . 37
6.1 WFS_EXEE_BIO_PRESENTSUBJECT . 37
6.2 WFS_EXEE_BIO_SUBJECTDETECTED . 38
6.3 WFS_EXEE_BIO_REMOVESUBJECT. 39
6.4 WFS_SRVE_BIO_SUBJECTREMOVED . 40
6.5 WFS_SRVE_BIO_DATACLEARED . 41
6.6 WFS_EXEE_BIO_ORIENTATION . 42
6.7 WFS_SRVE_BIO_DEVICEPOSITION . 43
6.8 WFS_SRVE_BIO_POWER_SAVE_CHANGE . 44
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7. Biometric Device Command Flows – Application Guidelines . 45
7.1 Biometric Enrollment Command Flow . 45
7.2 Biometric Match Command Flow – Separate Scan and Match . 46
7.3 Biometric Match Command Flow – Combined Scan and Match . 47
7.4 Biometric Scan-Only Command Flow . 48
8. C - Header file . 49
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European Foreword
This CEN Workshop Agreement has been developed in accordance with the CEN-CENELEC Guide 29
“CEN/CENELEC Workshop Agreements – The way to rapid consensus” and with the relevant provisions of
CEN/CENELEC Internal Regulations – Part 2. It was approved by a Workshop of representatives of interested
parties on 2022-11-08, the constitution of which was supported by CEN following several public calls for
participation, the first of which was made on 1998-06-24. However, this CEN Workshop Agreement does not
necessarily include all relevant stakeholders.
The final text of this CEN Workshop Agreement was provided to CEN for publication on 2022-11-18.
The following organizations and individuals developed and approved this CEN Workshop Agreement:

• AURIGA SPA
• CIMA SPA
• DIEBOLD NIXDORF SYSTEMS GMBH
• FIS BANKING SOLUTIONS UK LTD (OTS)
• FUJITSU TECHNOLOGY SOLUTIONS
• GLORY LTD
• GRG BANKING EQUIPMENT HK CO LTD
• HITACHI CHANNEL SOLUTIONS CORP
• HYOSUNG TNS INC
• JIANGSU GUOGUANG ELECTRONIC INFORMATION TECHNOLOGY
• KAL
• KEBA HANDOVER AUTOMATION GMBH
• NCR FSG
• NEXUS SOFTWARE
• OBERTHUR CASH PROTECTION
• OKI ELECTRIC INDUSTRY SHENZHEN
• SALZBURGER BANKEN SOFTWARE
• SECURE INNOVATION
• SIGMA SPA
It is possible that some elements of this CEN/CWA may be subject to patent rights. The CEN-CENELEC policy on
patent rights is set out in CEN-CENELEC Guide 8 “Guidelines for Implementation of the Common IPR Policy on
Patents (and other statutory intellectual property rights based on inventions)”. CEN shall not be held responsible for
identifying any or all such patent rights.
The Workshop participants have made every effort to ensure the reliability and accuracy of the technical and non-
technical content of CWA 16926-19, but this does not guarantee, either explicitly or implicitly, its correctness.
Users of CWA 16926-19 should be aware that neither the Workshop participants, nor CEN can be held liable for
damages or losses of any kind whatsoever which may arise from its application. Users of CWA 16926-19 do so on
their own responsibility and at their own risk.
The CWA is published as a multi-part document, consisting of:
Part 1: Application Programming Interface (API) - Service Provider Interface (SPI) - Programmer's Reference
Part 2: Service Classes Definition - Programmer's Reference
Part 3: Printer and Scanning Device Class Interface - Programmer's Reference
Part 4: Identification Card Device Class Interface - Programmer's Reference
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Part 5: Cash Dispenser Device Class Interface - Programmer's Reference
Part 6: PIN Keypad Device Class Interface - Programmer's Reference
Part 7: Check Reader/Scanner Device Class Interface - Programmer's Reference
Part 8: Depository Device Class Interface - Programmer's Reference
Part 9: Text Terminal Unit Device Class Interface - Programmer's Reference
Part 10: Sensors and Indicators Unit Device Class Interface - Programmer's Reference
Part 11: Vendor Dependent Mode Device Class Interface - Programmer's Reference
Part 12: Camera Device Class Interface - Programmer's Reference
Part 13: Alarm Device Class Interface - Programmer's Reference
Part 14: Card Embossing Unit Device Class Interface - Programmer's Reference
Part 15: Cash-In Module Device Class Interface - Programmer's Reference
Part 16: Card Dispenser Device Class Interface - Programmer's Reference
Part 17: Barcode Reader Device Class Interface - Programmer's Reference
Part 18: Item Processing Module Device Class Interface - Programmer's Reference
Part 19: Biometrics Device Class Interface - Programmer's Reference
Parts 20 - 28: Reserved for future use.
Parts 29 through 47 constitute an optional addendum to this CWA. They define the integration between the SNMP
standard and the set of status and statistical information exported by the Service Providers.
Part 29: XFS MIB Architecture and SNMP Extensions - Programmer’s Reference
Part 30: XFS MIB Device Specific Definitions - Printer Device Class
Part 31: XFS MIB Device Specific Definitions - Identification Card Device Class
Part 32: XFS MIB Device Specific Definitions - Cash Dispenser Device Class
Part 33: XFS MIB Device Specific Definitions - PIN Keypad Device Class
Part 34: XFS MIB Device Specific Definitions - Check Reader/Scanner Device Class
Part 35: XFS MIB Device Specific Definitions - Depository Device Class
Part 36: XFS MIB Device Specific Definitions - Text Terminal Unit Device Class
Part 37: XFS MIB Device Specific Definitions - Sensors and Indicators Unit Device Class
Part 38: XFS MIB Device Specific Definitions - Camera Device Class
Part 39: XFS MIB Device Specific Definitions - Alarm Device Class
Part 40: XFS MIB Device Specific Definitions - Card Embossing Unit Class
Part 41: XFS MIB Device Specific Definitions - Cash-In Module Device Class
Part 42: Reserved for future use.
Part 43: XFS MIB Device Specific Definitions - Vendor Dependent Mode Device Class
Part 44: XFS MIB Application Management
Part 45: XFS MIB Device Specific Definitions - Card Dispenser Device Class
Part 46: XFS MIB Device Specific Definitions - Barcode Reader Device Class
Part 47: XFS MIB Device Specific Definitions - Item Processing Module Device Class
Part 48: XFS MIB Device Specific Definitions - Biometrics Device Class
Parts 49 - 60 are reserved for future use.
Part 61: Application Programming Interface (API) - Migration from Version 3.40 (CWA 16296:2020) to Version
3.50 (this CWA) - Service Provider Interface (SPI) - Programmer's Reference
Part 62: Printer and Scanning Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version
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3.50 (this CWA) - Programmer's Reference
Part 63: Identification Card Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version
3.50 (this CWA) - Programmer's Reference
Part 64: Cash Dispenser Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version 3.50
(this CWA) - Programmer's Reference
Part 65: PIN Keypad Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version 3.50
(this CWA) - Programmer's Reference
Part 66: Check Reader/Scanner Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to
Version 3.50 (this CWA) - Programmer's Reference
Part 67: Depository Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version 3.50 (this
CWA) - Programmer's Reference
Part 68: Text Terminal Unit Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version
3.50 (this CWA) - Programmer's Reference
Part 69: Sensors and Indicators Unit Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to
Version 3.50 (this CWA) - Programmer's Reference
Part 70: Vendor Dependent Mode Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to
Version 3.50 (this CWA) - Programmer's Reference
Part 71: Camera Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version 3.50 (this
CWA) - Programmer's Reference
Part 72: Alarm Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version 3.50 (this
CWA) - Programmer's Reference
Part 73: Card Embossing Unit Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to
Version 3.50 (this CWA) - Programmer's Reference
Part 74: Cash-In Module Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version 3.50
(this CWA) - Programmer's Reference
Part 75: Card Dispenser Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version 3.50
(this CWA) - Programmer's Reference
Part 76: Barcode Reader Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version 3.50
(this CWA) - Programmer's Reference
Part 77: Item Processing Module Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to
Version 3.50 (this CWA) - Programmer's Reference
Part 78: Biometric Device Class Interface - Migration from Version 3.40 (CWA 16296:2020) to Version 3.50 (this
CWA) - Programmer's Reference
In addition to these Programmer's Reference specifications, the reader of this CWA is also referred to a
complementary document, called Release Notes. The Release Notes contain clarifications and explanations on the
CWA specifications, which are not requiring functional changes. The current version of the Release Notes is
available online from: https://www.cencenelec.eu/areas-of-work/cen-sectors/digital-society-cen/cwa-download-
area/.
The information in this document represents the Workshop's current views on the issues discussed as of the date of
publication. It is provided for informational purposes only and is subject to change without notice. CEN makes no
warranty, express or implied, with respect to this document.


Revision History:
3.40 December 06, 2019 Initial Release.
3.50 November 18, 2022 For a description of changes from version 3.40 to version
3.50 see the BIO 3.50 Migration document.

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1. Introduction
1.1 Background to Release 3.50
The CEN/XFS Workshop aims to promote a clear and unambiguous specification defining a multi-vendor software
interface to financial peripheral devices. The XFS (eXtensions for Financial Services) specifications are developed
within the CEN (European Committee for Standardization/Information Society Standardization System) Workshop
environment. CEN Workshops aim to arrive at a European consensus on an issue that can be published as a CEN
Workshop Agreement (CWA).
The CEN/XFS Workshop encourages the participation of both banks and vendors in the deliberations required to
create an industry standard. The CEN/XFS Workshop achieves its goals by focused sub-groups working
electronically and meeting quarterly.
Release 3.50 of the XFS specification is based on a C API and is delivered with the continued promise for the
protection of technical investment for existing applications. This release of the specification extends the
functionality and capabilities of the existing devices covered by the specification:
• Addition of E2E security
• PIN Password Entry
1.2 XFS Service-Specific Programming
The service classes are defined by their service-specific commands and the associated data structures, error codes,
messages, etc. These commands are used to request functions that are specific to one or more classes of Service
Providers, but not all of them, and therefore are not included in the common API for basic or administration
functions.
When a service-specific command is common among two or more classes of Service Providers, the syntax of the
command is as similar as possible across all services, since a major objective of XFS is to standardize function
codes and structures for the broadest variety of services. For example, using the WFSExecute function, the
commands to read data from various services are as similar as possible to each other in their syntax and data
structures.
In general, the specific command set for a service class is defined as a superset of the specific capabilities likely to
be provided by the developers of the services of that class; thus any particular device will normally support only a
subset of the defined command set.
There are three cases in which a Service Provider may receive a service-specific command that it does not support:
The requested capability is defined for the class of Service Providers by the XFS specification, the particular vendor
implementation of that service does not support it, and the unsupported capability is not considered to be
fundamental to the service. In this case, the Service Provider returns a successful completion, but does no operation.
An example would be a request from an application to turn on a control indicator on a passbook printer; the Service
Provider recognizes the command, but since the passbook printer it is managing does not include that indicator, the
Service Provider does no operation and returns a successful completion to the application.
The requested capability is defined for the class of Service Providers by the XFS specification, the particular vendor
implementation of that service does not support it, and the unsupported capability is considered to be fundamental
to the service. In this case, a WFS_ERR_UNSUPP_COMMAND error for Execute commands or
WFS_ERR_UNSUPP_CATEGORY error for Info commands is returned to the calling application. An example
would be a request from an application to a cash dispenser to retract items where the dispenser hardware does not
have that capability; the Service Provider recognizes the command but, since the cash dispenser it is managing is
unable to fulfil the request, returns this error.
The requested capability is not defined for the class of Service Providers by the XFS specification. In this case, a
WFS_ERR_INVALID_COMMAND error for Execute commands or WFS_ERR_INVALID_CATEGORY error
for Info commands is returned to the calling application.
This design allows implementation of applications that can be used with a range of services that provide differing
subsets of the functionalities that are defined for their service class. Applications may use the WFSGetInfo and
WFSAsyncGetInfo commands to inquire about the capabilities of the service they are about to use, and modify
their behavior accordingly, or they may use functions and then deal with error returns to make decisions as to how
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to use the service.
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2. Biometric Devices
Biometrics refers to metrics related to human characteristics and biology. Biometrics authentication can be used as
a form of identification and/or access control. This is an overview of biometrics, as well as an introduction to the
terminology used in this document. It introduces to XFS the concept of scanning a person’s biometric data in raw
image form (raw biometric data), then processing it into a smaller more concise form that is easier to manage
(biometric template data). The first scan of a user is called ENROLLMENT as the user is effectively being
enrolled into a scheme by recording their biometric data. Thereafter subsequent scans of the user can be compared
to the original data in order to verify who they say they are (VERIFICATION), or alternatively used to identify
them as a specific individual (IDENTIFICATION). These concepts are explained below in more detail.
2.1 Enrollment
The first time an individual uses a biometric device it is called Enrollment. During enrollment, biometric data from
an individual is captured and stored somewhere, for example on a smart card or in a server/host database. Normally
the raw biometric data captured will be processed and converted to a smaller format that is used for subsequent
comparison. This format is referred to in this document as a template. A template is a synthesis of the relevant
characteristics extracted from the original raw data. Elements of the biometric data that are not used in the matching
algorithm are discarded in the template to reduce the file size and to protect the identity of the enrollee.
2.2 Biometric Matching
During the matching phase, the obtained template is passed to a matcher which compares it to other existing
templates and a probable match is calculated, either as a Boolean true or false or as a threshold indicating the
likelihood of a match. With regard to matching, biometric systems commonly have two different basic modes of
operation: Verification and Identification:
Verification: performs a one-to-one comparison of captured biometric data with a specific template in order to
verify that an individual is the person they claim to be.
Identification: the system performs a one-to-many comparison of captured biometric data in order to establish a
person’s identity.

Note: The above diagram does not make any assumptions about where the actual matching takes place. The
interface provided is versatile enough to be able to support three basic Biometric systems:
Match on server: The biometric template data is stored on a server or host. When scanning takes place biometric
data is sent to the server, which does the actual identification or verification.
Match on card: The biometric enrollment data for an individual is stored on a smart card/personal device. The
device scans a user then returns the biometric template information to the application. This data is then sent to the
card, and an application on the smart card chip does the comparison, returning the result to the application.
Match on device: The biometric enrollment data for an individual is stored on a smart card or host. The enrollment
data is read from the card or host and into the device, which then compares it to scanned information, returning the
result to the application.
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2.3 Biometric Device Types
There are many different varieties of biometric hardware, this XFS biometrics specification supports three main
different types of device:
1. Devices which only support scanning and returning biometric data
In this case the device is a simple biometric scanning device, User data is scanned using the
WFS_CMD_BIO_READ command, but matching is performed externally, for example on a smart card or
on a server. In this case the WFS_CMD_BIO_MATCH and WFS_CMD_BIO_SET_MATCH commands
are not supported.
2. Devices which support a separate scan and match functionality
These devices scan and perform a comparison as separate operations. Existing biometric data is first
imported using the WFS_CMD_BIO_IMPORT command. When the WFS_CMD_BIO_READ command
is then called the scanned user data is temporarily stored. The WFS_CMD_BIO_MATCH command is
then called to perform the comparison and return the result.
3. Devices which support a combined scan and match functionality
These devices scan and perform a comparison as a single operation. Existing biometric data is first
imported using the WFS_CMD_BIO_IMPORT command. In this case the
WFS_CMD_BIO_SET_MATCH command must be called first, either as a one -time call or before each
WFS_CMD_BIO_READ command. The purpose of the WFS_CMD_BIO_SET_MATCH command is to
set the criteria for matching. When the WFS_CMD_BIO_READ command is then called it scans the
user’s biometric data and also performs the comparison as a single operation. The
WFS_CMD_BIO_MATCH command is then called to return the result of the comparison.
2.4 Biometric Data Security
It is recommended that biometric data should be treated with the same strict caution as any other identifying and
sensitive information. A well designed biometric data handling architecture should always be designed to protect
against internal tampering, external attacks and other malicious threats. There are various ways of implementing
good security of which three are listed below:
• Multi Modal Biometrics
A Uni-Modal biometric system relies on data taken from a single source of information for authentication,
for example a single fingerprint reading device. In contrast, Multi-Modal biometric systems work on the
premise that it is more secure to accept information from two or more biometric inputs. As an example a
user could provide a fingerprint in addition to facial recognition, a positive match from two physical
characteristics improves the chances of a positive identification and mitigates the possibility that biometric
data has been cloned.
• Data Encryption
Biometric data should be encrypted where possible. The BIO specification provides for this by allowing an
encryption key to be specified whenever data is exchanged between an application and a BIO Service
Provider. In addition, the key management interface methods of the PIN device class can be used for key
management. This can be done by using the standard XFS compound device mechanism to implement a
BIO Service provider as a compound device together with a PIN device class Service Provider. The device
compounding mechanism is described in the XFS API specification. In this case the BIO Service Provider
would implement the biometric methods necessary to read and return data, while the key loading,
reporting etc,. functions of the PIN Service Provider interface would be implemented in order to provide
key management.
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3. References
1. XFS Application Programming Interface (API)/Service Provider Interface ( SPI), Programmer’s Reference,
Revision 3.4050
2. ANSI INCITS 381-2004 Information Technology - Finger Image-Based Data Interchange Format.
3. ANSI INCITS 378-2004 Information Technology - Finger Minutiae Format for Data Interchange.
4. ISO/IEC 19794-4:2005 Information technology - Biometric data int
...