ISO/IEC 19794-7:2014

Information technology — Biometric data interchange formats — Part 7: Signature/sign time series data

This part of ISO/IEC 19794 specifies data interchange formats for signature/sign behavioural data captured in the form of a multi-dimensional time series using devices such as digitizing tablets or advanced pen systems. The data interchange formats are generic, in that they may be applied and used in a wide range of application areas where handwritten signs or signatures are involved. No application-specific requirements or features are addressed in this part of ISO/IEC 19794. This part of ISO/IEC 19794 contains — a description of what data may be captured, — three data formats for containing the data: a full format for general use, a compression format capable of holding the same amount of information as the full format but in compressed form, and a compact format for use with smart cards and other tokens that does not require compression/decompression but conveys less information than the full format, and — examples of data record contents and best practices in capture. Specifying which of the format types and which options defined in this part of ISO/IEC 19794 are to be applied in a particular application is out of scope; this needs to be defined in application-specific requirements specifications or application profiles. It is advisable that cryptographic techniques be used to protect the authenticity, integrity, and confidentiality of stored and transmitted biometric data; yet such provisions are beyond the scope of this part of ISO/IEC 19794. This part of ISO/IEC 19794 also specifies elements of conformance testing methodology, test assertions, and test procedures as applicable to this part of ISO/IEC 19794. It establishes test assertions on the structure and internal consistency of the signature/sign time series data formats defined in this part of ISO/IEC 19794 (type A level 1 and 2 as defined in ISO/IEC 19794‑1:2011/Amd.1), and semantic test assertions (type A level 3 as defined in ISO/IEC 19794‑1:2011/Amd.1). The conformance testing methodology specified in this part of ISO/IEC 19794 does not establish: — tests of other characteristics of biometric products or other types of testing of biometric products (e.g. acceptance, performance, robustness, security), — tests of conformance of systems that do not produce data records claimed to conform to the requirements of this part of ISO/IEC 19794.

Technologies de l'information — Formats d'échange de données biométriques — Partie 7: Données de série chronologique de signature/signe

General Information

• Status: Withdrawn
• Publication Date: 04-Feb-2014
• ICS: 35.040 - Information coding
• ICS: 35.240.15 - Identification cards. Chip cards. Biometrics
• Technical Committee: ISO/IEC JTC 1/SC 37 - Biometrics
• Drafting Committee: ISO/IEC JTC 1/SC 37 - Biometrics
• Current Stage: 9599 - Withdrawal of International Standard
• Completion Date: 29-Oct-2021

Relations

• Amended By: ISO/IEC 19794-7:2014/Amd 1:2015 - Information technology — Biometric data interchange formats — Part 7: Signature/sign time series data — Amendment 1: XML encoding
• Effective Date: 25-Dec-2021
• Revised: ISO/IEC 19794-7:2021 - Information technology — Biometric data interchange formats — Part 7: Signature/sign time series data
• Effective Date: 23-Apr-2020
• Revises: ISO/IEC 19794-7:2007 - Information technology — Biometric data interchange formats — Part 7: Signature/sign time series data
• Effective Date: 30-Jan-2010

Standards Content (Sample)

INTERNATIONAL ISO/IEC
STANDARD 19794-7
Second edition
2014-02-01
Information technology — Biometric
data interchange formats —
Part 7:
Signature/sign time series data
Technologies de l’information — Formats d’échange de données
biométriques —
Partie 7: Données de série chronologique de signature/signe
Reference number
ISO/IEC 19794-7:2014(E)
©
ISO/IEC 2014

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ISO/IEC 19794-7:2014(E)

COPYRIGHT PROTECTED DOCUMENT
© ISO/IEC 2014
All rights reserved. Unless otherwise specified, no part of this publication may be reproduced or utilized otherwise in any form
or by any means, electronic or mechanical, including photocopying, or posting on the internet or an intranet, without prior
written permission. Permission can be requested from either ISO at the address below or ISO’s member body in the country of
the requester.
ISO copyright office
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Tel. + 41 22 749 01 11
Fax + 41 22 749 09 47
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Published in Switzerland
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ISO/IEC 19794-7:2014(E)

Contents Page
Foreword .iv
1 Scope . 1
2 Conformance . 1
3 Normative references . 2
4 Terms and definitions . 2
5 Abbreviated terms . 4
6 Conventions . 4
6.1 Coordinate system . 4
6.2 Octet and bit order . 4
6.3 Registered format type identifiers . 4
7 Channels . 5
7.1 General . 5
7.2 Pen tip position channels: X, Y, Z . 6
7.3 Pen tip velocity channels: VX, VY . 6
7.4 Pen tip acceleration channels: AX, AY . 6
7.5 Time channel: T . 6
7.6 Time difference channel: DT . 6
7.7 Pen tip force channel: F . 6
7.8 Pen tip switch state channel: S . 7
7.9 Pen orientation channels: TX, TY, A, E, R . 7
8 Full format . 8
8.1 Record organisation . 8
8.2 General header . 9
8.3 Record body .10
9 Compact format .16
9.1 Record organisation .16
9.2 Comparison algorithm parameters template .17
9.3 Embedment in a CBEFF data structure .18
9.4 Record body .19
10 Compression format .19
10.1 Record organisation .19
10.2 General header .20
10.3 Record body .20
Annex A (normative) Conformance testing methodology .23
Annex B (informative) Best practices .
Data acquisition.71
Annex C (informative) ASN.1 specification of the compact format
.72
Annex D (informative) Signature/sign coding examples .75
Bibliography .77
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ISO/IEC 19794-7:2014(E)

Foreword
ISO (the International Organization for Standardization) and IEC (the International Electrotechnical
Commission) form the specialized system for worldwide standardization. National bodies that are
members of ISO or IEC participate in the development of International Standards through technical
committees established by the respective organization to deal with particular fields of technical
activity. ISO and IEC technical committees collaborate in fields of mutual interest. Other international
organizations, governmental and non-governmental, in liaison with ISO and IEC, also take part in the
work. In the field of information technology, ISO and IEC have established a joint technical committee,
ISO/IEC JTC 1.
International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2.
The main task of the joint technical committee is to prepare International Standards. Draft International
Standards adopted by the joint technical committee are circulated to national bodies for voting.
Publication as an International Standard requires approval by at least 75 % of the national bodies
casting a vote.
Attention is drawn to the possibility that some of the elements of this document may be the subject of
patent rights. ISO and IEC shall not be held responsible for identifying any or all such patent rights.
ISO/IEC 19794-7 was prepared by Joint Technical Committee ISO/IEC JTC 1, Information technology,
Subcommittee SC 37, Biometrics.
This second edition revises the first edition (ISO/IEC 19794-7:2007). Clauses 7 and 8 have been
technically revised and it has been amended by Clause 10 and Annex A. It also incorporates the Technical
Corrigendum ISO/IEC 19794-7:2007/Cor.1:2009.
ISO/IEC 19794 consists of the following parts, under the general title Information technology — Biometric
data interchange formats:
— Part 1: Framework
— Part 2: Finger minutiae data
— Part 3: Finger pattern spectral data
— Part 4: Finger image data
— Part 5: Face image data
— Part 6: Iris image data
— Part 7: Signature/sign time series data
— Part 8: Finger pattern skeletal data
— Part 9: Vascular image data
— Part 10: Hand geometry silhouette data
— Part 11: Signature/sign processed dynamic data
— Part 14: DNA data
The following part is under preparation:
— Part 13:Voice data
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INTERNATIONAL STANDARD ISO/IEC 19794-7:2014(E)
Information technology — Biometric data interchange
formats —
Part 7:
Signature/sign time series data
1 Scope
This part of ISO/IEC 19794 specifies data interchange formats for signature/sign behavioural data
captured in the form of a multi-dimensional time series using devices such as digitizing tablets or
advanced pen systems. The data interchange formats are generic, in that they may be applied and used
in a wide range of application areas where handwritten signs or signatures are involved. No application-
specific requirements or features are addressed in this part of ISO/IEC 19794.
This part of ISO/IEC 19794 contains
— a description of what data may be captured,
— three data formats for containing the data: a full format for general use, a compression format capable
of holding the same amount of information as the full format but in compressed form, and a compact
format for use with smart cards and other tokens that does not require compression/decompression
but conveys less information than the full format, and
— examples of data record contents and best practices in capture.
Specifying which of the format types and which options defined in this part of ISO/IEC 19794 are to
be applied in a particular application is out of scope; this needs to be defined in application-specific
requirements specifications or application profiles.
It is advisable that cryptographic techniques be used to protect the authenticity, integrity, and
confidentiality of stored and transmitted biometric data; yet such provisions are beyond the scope of
this part of ISO/IEC 19794.
This part of ISO/IEC 19794 also specifies elements of conformance testing methodology, test assertions,
and test procedures as applicable to this part of ISO/IEC 19794. It establishes test assertions on the
structure and internal consistency of the signature/sign time series data formats defined in this part
of ISO/IEC 19794 (type A level 1 and 2 as defined in ISO/IEC 19794-1:2011/Amd.1), and semantic test
assertions (type A level 3 as defined in ISO/IEC 19794-1:2011/Amd.1).
The conformance testing methodology specified in this part of ISO/IEC 19794 does not establish:
— tests of other characteristics of biometric products or other types of testing of biometric products
(e.g. acceptance, performance, robustness, security),
— tests of conformance of systems that do not produce data records claimed to conform to the
requirements of this part of ISO/IEC 19794.
2 Conformance
A biometric data record conforms to this part of ISO/IEC 19794 if it satisfies the format requirements with
respect to its structure, with respect to relations among its fields, and with respect to relations between
its fields and the underlying input that are specified within clauses 6–10 of this part of ISO/IEC 19794.
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ISO/IEC 19794-7:2014(E)

Biometric data interchange format conformance tests conform to this part of ISO/IEC 19794 if they
satisfy all of the normative requirements set forth in Annex A. Specifically, all level-1, level-2, and level-3
tests shall use the test assertions defined in Table A.2, Table A.3, and Table A.4 of clause A.2 in conformity
with the concept and rules set in ISO/IEC 19794-1:2011/Amd.1.
Implementations of this part of ISO/IEC 19794 tested according to the specified methodology shall be
able to claim conformance only to those biometric data record requirements specified in this part of
ISO/IEC 19794 that are tested by the test methods established by this methodology.
Implementations of this part of ISO/IEC 19794 do not necessarily need to conform to all possible aspects
of this part of ISO/IEC 19794, but only to those requirements that are claimed to be supported by the
implementation in an implementation conformance statement (ICS), filled out in accordance with
ISO/IEC 19794-1:2011/Amd.1 and Table A.1 of clause A.1 of this part of ISO/IEC 19794.
3 Normative references
The following referenced documents are indispensable for the application of this document. For dated
references, only the edition cited applies. For undated references, the latest edition of the referenced
document (including any amendments) applies.
ISO/IEC 8825-1, Information technology — ASN.1 encoding rules: Specification of Basic Encoding Rules
(BER), Canonical Encoding Rules (CER) and Distinguished Encoding Rules (DER) — Part 1
ISO/IEC 19785-1, Information technology — Common Biometric Exchange Formats Framework — Part 1:
Data element specification
ISO/IEC 19785-2, Information technology — Common Biometric Exchange Formats Framework — Part 2:
Procedures for the operation of the Biometric Registration Authority
ISO/IEC 19785-3, Information technology — Common Biometric Exchange Formats Framework — Part 3:
Patron format specifications
ISO/IEC 19794-1:2011, Information technology — Biometric data interchange formats — Part 1: Framework
4 Terms and definitions
For the purposes of this document, the terms and definitions given in ISO/IEC 19794-1:2011 and the
following apply.
4.1
channel
data item (captured, intermediate, or processed) recorded in form of a time series
EXAMPLE pen tip position x and y coordinates, pen tip force, pen tilt along the x and y axes, pen azimuth, pen
elevation, pen rotation
4.2
compression
process that reduces the size of a digital file with or without loss of information
Note 1 to entry: The compression format defined in clause 10 includes data compressed by lossless compression
schemes.
4.3
pen azimuth
angle measured clockwise from the positive y axis to the perpendicular projection of the pen onto the
writing plane
Note 1 to entry: The pen azimuth may range from 0° to 360°.
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4.4
pen-down event
event from which on the pen tip is touching the writing plane
4.5
pen elevation
angle between the perpendicular projection of the pen onto the writing plane and the pen
Note 1 to entry: The pen elevation may range from 0° to 90°.
4.6
pen rotation
angle of the rotation of the pen about its longitudinal axis measured counter-clockwise from a device-
specific rotational reference position
Note 1 to entry: The pen rotation may range from 0° to 360°.
4.7
pen tilt along the x axis
angle measured clockwise from the positive z axis to the perpendicular projection of the pen onto the
x,z plane
Note 1 to entry: The pen tilt along the x axis may range from –90° to +90°.
4.8
pen tilt along the y axis
angle measured clockwise from the positive z axis to the perpendicular projection of the pen onto the
y,z plane
Note 1 to entry: The pen tilt along the y axis may range from –90° to +90°.
4.9
pen-up event
event from which on the pen tip is not touching the writing plane, after a pen-down event
4.10
sampling rate
number of samples per second (or per other unit) taken from a continuous signal to make a discrete
signal
4.11
signature/sign representation
data recorded from a single signature/sign
4.12
X jitter
sample standard deviation of at least 100 x coordinate samples from a stationary pen
4.13
Y jitter
sample standard deviation of at least 100 y coordinate samples from a stationary pen
4.14
X pixel density
number of dots per millimetre that the capture device resolves in the x (horizontal) direction
4.15
Y pixel density
number of dots per millimetre that the capture device resolves in the y (vertical) direction
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5 Abbreviated terms
lsb least significant bit
msb most significant bit
6 Conventions
6.1 Coordinate system
The coordinate system used to express the pen position shall be a three-dimensional Cartesian coordinate
system. The x axis shall be the horizontal axis of the writing plane, with x coordinates increasing to the
right. The y axis shall be the vertical axis of the writing plane, with y coordinates increasing upwards.
The z axis shall be the axis perpendicular to the writing plane, with z coordinates increasing upwards
out of the writing plane starting from 0. For an illustration see Figure 1.
z
y
Writing plane
0
x
Figure 1 — Coordinate system
NOTE The origin of x and y coordinates is not specified here. Depending on the used technology, it may be, for
instance, in the centre of the writing pad, at its lower left corner, or at the pen position at the first pen-down event.
6.2 Octet and bit order
The more significant bytes of any multi-byte quantity are stored at lower addresses in memory than
(and are transmitted before) less significant bytes.
Within a byte, the bits are numbered from 8 to 1, where bit 8 is the ‘most significant bit’ (msb) and bit 1
the ‘least significant bit’ (lsb).
6.3 Registered format type identifiers
The data records specified in this part of ISO/IEC 19794 may be embedded in a CBEFF- (ISO/IEC 19785-
1) compliant biometric information record (BIR). This clause lists the BDB (biometric data block) format
owner identifier and the BDB format type identifiers that shall be used if embedded in a CBEFF BIR.
These identifiers are registered with IBIA, the CBEFF Registration Authority (see ISO/IEC 19785-2).
The format owner of the formats defined in ISO/IEC 19794 is ISO/IEC JTC 1/SC 37. The format owner
identifier is 257 (0101 ). Table 1 lists the format type identifiers for the formats defined in this part
Hex
of ISO/IEC 19794.
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Table 1 — Format type identifiers
CBEFF BDB format Short name Full object identifier
type identifier
14 (000e ) signature-sign-time- {iso(1) registration-authority(1) cbeff(19785) biometric-organization(0)
Hex
series-full jtc1-sc37(257) bdbs(0) signature-sign-time-series-full(14)}
15 (000f ) signature-sign-time- {iso(1) registration-authority(1) cbeff(19785) biometric-organization(0)
Hex
series-compact jtc1-sc37(257) bdbs(0) signature-sign-time-series-compact(15)}
30 (001e ) signature-sign-time- {iso(1) registration-authority(1) cbeff(19785) biometric-organization(0)
Hex
series-compression jtc1-sc37(257) bdbs(0) signature-sign-time-series-compression(30)}
NOTE 1 The format type identifier for the full format defined in this edition of ISO/IEC 19794-7 is the same
as the one for the full format defined in ISO/IEC 19794-7:2007. An indication of which version of the full format
applies can be determined from the version number included in the general header.
NOTE 2 The compact format defined in this edition of ISO/IEC 19794-7 is the same as the one defined in
ISO/IEC 19794-7:2007. Hence, the format type identifier for the compact format defined in this edition of
ISO/IEC 19794-7 is also the same as the one for the compact format defined in ISO/IEC 19794-7:2007.
7 Channels
7.1 General
Table 2 lists the channel names and their meanings. Signature/sign time series data captured with
different capture devices or used in different applications may contain data from different channels.
Either the T channel or the DT channel shall be present, or uniform sampling (constant time difference
between adjacent sample points) shall be indicated (see clause 7.6). Inclusion of at least one other channel
is mandatory.
Table 2 — Channels
Channel Description
name
X x coordinate (horizontal pen position)
Y y coordinate (vertical pen position)
Z z coordinate (height of pen above the writing plane)
VX velocity in x direction
VY velocity in y direction
AX acceleration in x direction
AY acceleration in y direction
T time
DT time difference
F pen tip force
S pen tip switch state (touching/not touching the writing plane)
TX pen tilt along the x axis
TY pen tilt along the y axis
A pen azimuth
E pen elevation
R pen rotation
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7.2 Pen tip position channels: X, Y, Z
There are three channels defined for recording pen tip position data in the three-dimensional space.
The X channel is for recording the x coordinate of the projection of the pen tip on the writing plane. The
Y channel is for recording the y coordinate of the projection of the pen tip on the writing plane. The Z
channel is for recording the height of the pen tip above the writing plane.
The unit of measurement is millimetres (mm). To restore the actual values, the integer values given
in the record body are to be divided by a scaling value given in the channel description. By choosing
appropriate scaling values, different degrees of accuracy can be expressed.
7.3 Pen tip velocity channels: VX, VY
The VX channel is for recording the pen tip velocity along the x axis. The VY channel is for recording the
pen tip velocity along the y axis.
The unit of measurement is millimetres per second (mm/s). To restore the actual values, the integer
values given in the record body are to be divided by a scaling value given in the channel description. By
choosing appropriate scaling values, different degrees of accuracy can be expressed.
7.4 Pen tip acceleration channels: AX, AY
The AX channel is for recording the pen tip acceleration along the x axis. The AY channel is for recording
the pen tip acceleration along the y axis.
2
The unit of measurement is millimetres per square second (mm/s ). To restore the actual values,
the integer values given in the record body are to be divided by a scaling value given in the channel
description. By choosing appropriate scaling values, different degrees of accuracy can be expressed.
7.5 Time channel: T
The T channel is for recording the time elapsed since the first sample.
The unit of measurement is seconds (s). To restore the actual values, the integer values given in the
record body are to be divided by a scaling value given in the channel description. By choosing appropriate
scaling values, different degrees of accuracy can be expressed.
7.6 Time difference channel: DT
The DT channel is for recording the time elapsed since the previous sample point.
The unit of measurement is seconds (s). To restore the actual values, the integer values given in the
record body are to be divided by a scaling value given in the channel description. By choosing appropriate
scaling values, different degrees of accuracy can be expressed.
In case of uniform sampling, the channel inclusion field (see clause 8.3.2.8.1) in the representation
header should indicate the DT channel as present, but the DT channel values should be absent in the
representation body while the channel description preamble (see clause 8.3.2.8.2) for the DT channel
indicates the time differences between adjacent sample points as constant.
7.7 Pen tip force channel: F
The F channel is for recording the magnitude of the pen tip force.
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The unit of measurement is Newton (N). To restore the actual values, the integer values given in the
record body are to be divided by a scaling value given in the channel description. By choosing appropriate
scaling values, different degrees of accuracy can be expressed.
NOTE The direction of the pen-tip force depends on the capture device technology, which is identified by the
capture device technology identifier.
7.8 Pen tip switch state channel: S
The S channel is for recording whether the pen tip touches the writing plane or not. The value shall be 0
in case that the pen tip does not touch the writing plane. In case of pen-down events, the value shall also
be 0. The value shall be 1 in case that the pen tip touches the writing plane. In case of pen-up events, the
value shall also be 1.
NOTE Temporarily maintaining a value of 0 when the pen tip starts touching the writing plane allows a
recognition of pen-down events even if the capture device provides no sample points for pen-up strokes.
7.9 Pen orientation channels: TX, TY, A, E, R
There are five channels defined for recording pen orientation data. The A channel is for recording the
pen azimuth. The E channel is for recording the pen elevation. The TX channel is for recording the pen
tilt along the x axis. The TY channel is for recording the pen tilt along the y axis. The R channel is for
recording the rotation of the pen about its longitudinal axis. It may be chosen to use
— pen azimuth and pen elevation or
— pen tilt along the x and y axes
with or without the pen rotation. For illustrations see Figure 2 and Figure 3.
The unit of measurement for the pen orientation angles is degree (°).To restore the actual values,
the integer values given in the record body are to be divided by a scaling value given in the channel
description. By choosing appropriate scaling values, different degrees of accuracy can be expressed.
Figure 2 — Pen orientation angles
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Figure 3 — Pen rotation
8 Full format
8.1 Record organisation
A signature/sign time series data record in the full format shall consist of the following data elements
in the given order:
— a general header, containing descriptive information about the structure and contents of the data
record, and
— a record body, containing at least one signature/sign representation.
Figure 4 depicts a signature/sign time series data record in full format. The solid boxes indicate fields
that shall be present. The dashed boxes indicate optional fields. The length of each field in bytes is
indicated in parentheses at the bottom of the corresponding box. The ellipses indicate that more fields
of the same format may follow.
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General header Record body
(15) (variable)
Representation 1
Format identifier Version number Record length Number of Certifi- Representation m
representa- cation
……
tions flag
(4) (4) (4) (2) (1) (variable) (variable)
Representation Representation
header body
(variable) (variable)
Representation Capture date Capture Capture Capture Quality record Channel Number of Sequence of Extended Extended data
length and time device device device descriptio
...