Scientific and technological reports

Smart Cards: The Coding of User Interface Requirements

Dr. John Gill, Chief Scientist, RNIB
Graham Carson, ORGA Card Systems (UK) Ltd
July 1996

1. Scope

This document provides the necessary information on the data elements to be stored within a Smart Card and exchanged in order to enable Integrated Circuit (IC) Card accepting terminals to identify specific user interface preferences. The preference information may be used by terminals to configure appropriate methods of communicating with the user during a transaction process.

This document also provides a mechanism for the retrieval of the user preference information from an Integrated Circuit Card and for the combination of data elements to form particular user profiles.

Formats and detailed definitions of single data elements are defined, however, the exact method of storage of data within the IC Card is outside the scope of this document.

This document has been prepared by ORGA Card Systems (UK) Ltd as part of the European SATURN Project. Further information may be obtained from:-

Dr John Gill, RNIB, 105 Judd Street, London WC1H 9NE
(Fax: +44 20 7391 2318; Email: john.gill@rnib.org.uk)

Graham Carson, ORGA Card Systems (UK) Ltd, 6 Greys Road, Henley-on-Thames, Oxon RG9 1RY (Fax: +44 1491 419295; Email: gcarson@orga.co.uk)

2. Normative References

This document incorporates by dated or undated reference, provisions from other publications. These normative references are cited at the appropriate places in the text and the publications are listed hereafter. For dated references, subsequent amendments to, or revisions of any of these publications apply to this document only when incorporated in it by amendment or revision. For undated references, the latest edition of the publication referred to applies.

Saturn Project	1996	Smart Cards - Interfaces For People With Disabilities (ISBN: 1 86048 007 1)
IS 8825	1990	Information Technology - Open Systems Interconnection - Specification for Basic Encoding Rules for Abstract Syntax Notation One (ASN.1)
IS 7816-4	1995	Information Technology - Identification Cards - Integrated Circuit Cards with Contacts. Part 4: Interindustry Commands For Interchange.
IS 7816-6	1996	Information Technology - Identification Cards - Integrated Circuit Cards with Contacts. Part 6: Inter-industry Data Elements.
IS 8859-1	1987	Information Processing - 8-bit single-byte coded graphic character sets. Part 1: Latin alphabet No. 1.
IS 639	1988	Codes for the representation of names of languages.

3. Definitions, symbols and abbreviations

3.1 Definitions

For the purposes of this document, the following definitions apply:

composite data element: a data element made up of a concatenation of data elements.

data element: as defined in IS 7816-4.

data object: as defined in IS 7816-4.

3.2 Abbreviations

For the purposes of this document, the following abbreviations apply:

ASN.1 Abstract syntax notation one

b1.b8 Bit one to eight of a byte

ls least significant byte

ms most significant byte

PIN Personal Identification Number

TLV Tag, length, value.

4. User Interface Data Elements

4.1 General Remarks

For each data element, the following descriptors may be present:-

- purpose (a short description of the use of the given data element);

- format (giving the size of the data element and possibly a symbolic format used to describe the content);

- content (the exact definition for the coding of the data element);

- remarks (other information).

4.2 Principles

The following principles apply to the identification of user preference data elements within this document:

- a data element is generally presented in the value field of a data object.

- a data object is the concatenation of the following string of bytes:

- a mandatory tag field, referred to as a tag;

- a mandatory length field indicating the number of bytes of the value field;

- a conditional value field of L bytes (when ‘L’ is not equal to ‘00’).

4.3 Data Object Structure

The following data object structures are supported:

- primitive data object

where T = Tag, L = Length, V = Value

- constructed data object

T₁

L₁

V₁

T₂

L₂

V₂

...

T_n

L_n

V_n

T = Tag of constructed data object

L = Length of the string (template) T₁ to V_n

T₁ = Tag of a data object

L₁ = Length of V1

V₁ = Value

4.3.1 Structure of the Tag

The tag consists of one or two bytes. The coding of these bytes shall be consistent with the basic encoding rules of ASN.1 (IS 8825). Table 1 defines the first byte.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
0	0	-	-	-	-	-	-	Not defined in this document.
0	1	-	-	-	-	-	-	Defined in this document. Application class, unambiguous identification.
1	0	-	-	-	-	-	-	Defined in this document and only to be used within a template.
1	1	-	-	-	-	-	-	Not defined in this document. Reserved for private use.
-	-	0	-	-	-	-	-	Primitive data object.
-	-	1	-	-	-	-	-	Constructed data object.
-	-	-	1	1	1	1	1	Tag number contained in the next byte - range 31..127
-	-	-	x	x	x	x	x	Tag number - range 0 - 30 Not all equal to 1.

Table 1 : Structure of the first byte of the Tag

The coding of the second byte of the tag, when present, is:

b8 = 0

b7 to b1 = binary value of the tag number in the range 31..127.

4.3.2 Structure of the Length

All lengths are expressed in bytes.

The length consists of one or more bytes. The coding of these bytes shall be consistent with the basic encoding rules of ASN.1 and shall be as defined in table 2.

Range	No. of bytes	1st byte	2nd byte	3rd byte
0..127	1	binary value	none	none
0..255	2	‘81’	binary value	none
0..65,535	3	‘82’	binary ms byte	value ls byte

Table 2 - Coding of the length value

ms = most significant byte, ls = least significant byte.

4.4 List of Data Elements

This subclause defines data elements which may be present within an IC Card to indicate user interface preferences.

4.4.1 Symbols

Purpose: To indicate the preferred method of presentation of visual information, either via text, symbols, Braille or a combination of both.

Format: 1 byte.

Content: The content of this field is according to table 3.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	-	-	-	-	-	-	1	Text required
-	-	-	-	-	-	1	-	Symbols required
-	-	-	-	-	1	-	-	Sign language required
-	-	-	-	1	-	-	-	Braille output required
x	x	x	x	-	-	-	-	Reserved for future use. All bits set to zero.

Table 3 : Content of the Symbols Data Element

Remarks: This data element is addressed through the use of Tag number ‘DF 50’.

4.4.2 Text Size

Purpose: This data element enables the preferred size of any text information to be provided to the terminal device.

Format: 1 byte.

Content: The height of text in millimetres. The width of text shall be in proportion to the specified height for the particular font being displayed.

Remarks: This data element is addressed through the use of Tag number ‘DF 51’.

4.4.3 Screen Colour

Purpose: To indicate preferred colours for the presentation of visual information.

Format: 1 byte.

Content: The coding of the Screen Colour byte shall be according to table 4.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	-	-	-	-	x	x	x	Preferred colour for text according to the values specified below
-	-	x	x	x	-	-	-	Preferred background colour according to the values specified below
x	x	-	-	-	-	-	-	Reserved for future use. All bits set to zero.

Table 4 : Content of the Screen Colours Data Element

Colour coding scheme for text and background:-

000 : white

001 : red

010 : orange

011 : yellow

100 : green

101 : blue

110 : purple

111 : black

Remarks: This data element is addressed through the use of Tag number ‘DF 52’.

4.4.4 Colour Avoidance

Purpose: To indicate specific colours or combination of colours to be avoided when displaying visual information to the user.

Format: 1 byte.

Content: The coding of the Colour Avoidance byte shall be according to table 5.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	-	-	-	-	-	-	0	Avoid display of information in red.
-	-	-	-	-	-	-	1	Reserved for future use.
-	-	-	-	-	-	0	-	Avoid red/green colour combination.
-	-	-	-	-	-	1	-	Avoid blue/yellow colour combination.
x	x	x	x	x	x	-	-	Reserved for future use. All bits set to zero.

Table 5 : Content of the Colour Avoidance Data Element

Remarks: This data element is addressed through the use of Tag number ‘DF 53’.

4.4.5 Position Of Screen

Purpose: To enable automatic height positioning of a screen to assist users in the reading of information.

Format: 1 byte coded as two BCD digits.

Content: The value of this element denotes the desired height of the centre of a visual display in decimetres from ground level.

Remarks: This data element is addressed through the use of Tag number ‘DF 54’.

4.4.6 Voice Output

Purpose: To indicate the preferred device for the voice related information.

Format: 1 byte binary.

Content: The coding of the Voice Output byte shall be according to table 6.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	-	-	-	-	-	-	1	Loudspeaker output required
-	-	-	-	-	-	1	-	Headset output required.
-	-	-	-	-	1	-	-	Hearing aid - magnetic inductive coupling required.
x	x	x	x	x	-	-	-	Reserved for future use. All bits set to zero.

Table 6 : Content of the Voice Output Data Element

Remarks: This data element is addressed through the use of Tag number ‘DF 55’.

4.4.7 Sound Amplification

Purpose: To enable sound amplification to be performed by the terminal for voice or other output information.

Format: 1 byte binary.

Content: The coding of the Sound Amplification byte shall be according to table 7.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	x	x	x	x	x	x	x	Offset amount in dBA from the terminal’s normal sound level.
0	-	-	-	-	-	-	-	Positive value denoted in bits b1 to b7.
1	-	-	-	-	-	-	-	Negative value denoted in bits b1 to b7.

Table 7 : Content of the Sound Amplification Data Element

Remarks: This data element is addressed through the use of Tag number ‘DF 56’.

4.4.8 High Frequency Amplification

Purpose: To enable sound amplification to be performed by the terminal for high frequency voice or other output information.

Format: 1 byte binary.

Content: The coding of the High Frequency Amplification byte shall be according to table 8.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	x	x	x	x	x	x	x	Offset amount in dBA from the terminal’s normal sound level.
0	-	-	-	-	-	-	-	Positive value denoted in bits b1 to b7.
1	-	-	-	-	-	-	-	Negative value denoted in bits b1 to b7.

Table 8 : Content of the High Frequency Amplification Data Element

Remarks: This data element is addressed through the use of Tag number ‘DF 57’.

4.4.9 Low Frequency Amplification

Purpose: To enable sound amplification to be performed by the terminal for low frequency voice or other output information.

Format: 1 byte binary.

Content: The coding of the Low Frequency Amplification byte shall be according to table 9.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	x	x	x	x	x	x	x	Offset amount in dBA from the terminal’s normal sound level.
0	-	-	-	-	-	-	-	Positive value denoted in bits b1 to b7.
1	-	-	-	-	-	-	-	Negative value denoted in bits b1 to b7.

Table 9 : Content of the Low Frequency Amplification Data Element

Remarks: This data element is addressed through the use of Tag number ‘DF 58’.

4.4.10 Input Requirements

Purpose: To indicate the preferred method for input of data into the terminal.

Format: 1 byte binary.

Content: The coding of the Input Requirements byte shall be according to table 10.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	-	-	-	-	-	-	1	Voice input required
-	-	-	-	-	-	1	-	Keyboard input required
-	-	-	-	-	1	-	-	PIN Pad top row denotes the digits 1,2,3.
-	-	-	-	1	-	-	-	PIN Pad top row denotes the digits 7,8,9.
x	x	x	x	-	-	-	-	Reserved for future use. All bits set to zero.

Table 10 : Content of the Input Requirements Data Element

Remarks: This data element is addressed through the use of Tag number ‘DF 59’.

4.4.11 Touch Screen

Purpose: To indicate the preferred layout and icon characteristics for a touch screen input device.

Format: 1 byte binary.

Content: The coding of the Touch Screen byte shall be according to table 11.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	-	-	-	-	-	0	0	Normal button size required
-	-	-	-	-	-	0	1	Medium button size required
-	-	-	-	-	-	1	0	Large button size required
-	-	-	-	-	-	1	1	Very large button size required
-	-	-	-	-	0	-	-	Click up required
-	-	-	-	-	1	-	-	Click down required
-	-	-	0	0	-	-	-	Low sensitivity required
-	-	-	0	1	-	-	-	Normal sensitivity required
-	-	-	1	0	-	-	-	Moderate sensitivity required
-	-	-	1	1	-	-	-	High sensitivity required
x	x	x	-	-	-	-	-	Reserved for future use. All bits set to zero.

Table 11 : Content of the Touch Screen Data Element

Remarks: This data element is addressed through the use of Tag number ‘DF 5A’.

4.4.12 Position of Input Device

Purpose: To enable automatic height positioning of a data input device to assist users in the entry of information.

Format: 1 byte coded as two BCD digits.

Content: The value of this element denotes the desired height of the centre of the input device in decimetres from ground level.

Remarks: This data element is addressed through the use of Tag number ‘DF 5B’.

4.4.13 Time-Outs

Purpose: To indicate a requirement for additional time to complete user input processes, thus reducing the potential for errors caused by device time-outs.

Format: 2 digits numeric.

Content: The number of decaseconds of time required before time-outs shall come into force.

Remarks: This data element is addressed through the use of Tag number ‘DF 5C’.

4.4.14 Language

Purpose: To indicate up to 4 preferred language(s) in order of appeal for the user interface.

Format: 2 alphabetic characters per language.

Content: This element is coded in accordance with IS 639.

Remarks: This data element is addressed through the use of Tag number ‘5F 2D’ as defined in IS 7816-6.

4.4.15 Interface Complexity Level

Purpose: To indicate the preferred level of complexity for dialogue or text presented to the user.

Format: 1 byte binary.

Content: The coding of the Interface Complexity Level byte shall be according to table 12.

b8	b7	b6	b5	b4	b3	b2	b1	Meaning
-	-	-	-	-	-	0	0	Normal dialogue required
-	-	-	-	-	-	0	1	Simple dialogue level required
-	-	-	-	-	-	1	0	Very simple dialogue required
-	-	-	-	-	-	1	1	Reserved for future use..
-	-	-	-	0	0	-	-	Normal text complexity required
-	-	-	-	0	1	-	-	Simple text complexity required
-	-	-	-	1	0	-	-	Very simple text complexity required
-	-	-	-	1	1	-	-	Reserved for future use
-	-	0	0	-	-	-	-	Normal text density required
-	-	0	1	-	-	-	-	Low text density required
-	-	1	0	-	-	-	-	Very low text density required
-	-	1	1	-	-	-	-	Reserved for future use
x	x	-	-	-	-	-	-	Reserved for future use. Both bits set to zero.

Table 12 : Content of the Interface Complexity Level Data Element

Remarks: This data element is addressed through the use of Tag number ‘DF 5D’.

4.4.16 Application Independent Requirements

Purpose: To indicate the set of user requirements independent of the application being implemented.

Format: n bytes binary (n is dependent on the number of requirements specified).

Content: A constructed data element comprising the individual interface requirements.

Remarks: This data element is addressed through the use of Tag number ‘FF 60’. This data element may be retrieved following application selection using the GET DATA command referencing the Tag number within the content of the command message.

4.4.17 Application Specific Requirements

Purpose: To indicate the set of user requirements which are specific to the application being implemented.

Format: n bytes binary (n is dependent on the number of requirements specified).

Content: A constructed data element comprising the individual interface requirements.

Remarks: This data element is addressed through the use of Tag number ‘FF 61’. This data element may be retrieved using the GET DATA command referencing the Tag number within the content of the command message. This data element may be replicated in the event of a multi-application card, particularly where the terminal is required to perform different actions on the same data element.