Note: Descriptions are shown in the official language in which they were submitted.
CA 02333589 2000-11-28
WO 99/63492 PCT/GB99/01688
-1-
VISUAL CODE RECORDAL AND COMMUNICATION THEREOF
This invention relates to the visual recordal of codes and
to the communication thereof to data processing machines.
There is a widespread need nowadays for individuals to use,
and by implication to remember, authentication codes.
These are to typically four digit numeric codes called
personal identification numbers or PINS. For security
reasons, these codes should not be written down. If the
user does find it necessary to write down the code in order
to remember it, it should certainly not be kept with the
card or document to which it relates.
Cards of various kinds proliferate. They are typically
identity cards or benefit cards. In these senses, identity
cards serve essentially to identify the card holder,
whereas benefit cards will typically also have financial
implications, and include credit cards, debit cards, and
charge cards. While commonly referred to as cards, these
items are typically made of a plastics material, and are
usually of a standard size, about 85mm by 54mm.
These cards are often associated with a machine-readable
element, such as an encoded magnetic stripe, or may be so-
called smart cards with electrical contacts and integrated
microcircuitry, which give the card a specific, commonly
unique, identity. A PIN may then be required to validate
the use of such a card.
CA 02333589 2000-11-28
WO 99/63492 PCT/GB99/01688
-2-
Patent Application W093/11511 (also GB2276967) describes
personal identification devices and access control systems
based on the use of complex images, typically images of
human faces. Complex images are considered to be images
that are recognisable if already known but not readily
capable of unique description to a person to whom they are
not known. Reference should be made to W093/11511 for
further discussion and understanding of what is meant by
complex images in this context, and for a discussion of the
abilities of human subjects to memorize and recall images
of human faces.
The invention described in W090/11511 is concerned with the
integrity of security systems. The present invention, in
contrast, is concerned with providing assistance to an
individual to record or remember his PIN in a
relatively secure manner. In that earlier disclosure,
faces stored by a computer are displayed in shifting
positions. In the present invention, to be described
herein, the images are continually displayed in fixed
positions. In one implementation they can be printed
permanently on the card itself. The feature in common with
W093/11511 is making use of the ability of the human mind
to recognise images, and to pick out remembered images from
a group of images, even if they are not wholly memorized in
all their details.
By means of the present invention, a four digit PIN can in
effect be securely recorded on one face of a card by
encoding each digit of the PIN in an array of, say, 9 or 10
images of different human faces. Instead of memorizing a
sequence of four digits, the PIN holder memorizes four
faces. Each array of images is formed in a regular manner,
for example as a three by three or five by two grid, so
CA 02333589 2000-11-28
WO 99/63492 PCT/GB99I01688
-3-
that each element of the array can be assigned a number
from 1 to 9 or from 0 to 9 respectively. The four arrays
can be set out in a defined sequence. Then, the set of
four arrays serves as an aide memoire: the user can easily
learn to recognise the four key faces, pick them out of the
different grids, and by their position and sequence
reconstruct the PIN.
Having recognised the faces, the user will need to
interpret them to a data terminal. The images may be
numbered explicitly, or implicitly by the order in which
they appear in the arrays. Likewise, the sequence of the
arrays can be explicitly numbered or can be implied by the
order in which they are displayed. For convenience, a
numeric code can be assumed, and this can be entered by a
standard numeric keypad marked with the numbers. Of
course, the images can be labelled with other characters or
symbols, and the keypad marked accordingly, or a separate
concordance can be provided.
The term "keypad" is used for convenience in this
description and claims, but it should be assumed to have a
general functional meaning. It might be a simple array of
9 or 10 keys, operated in a standard way, or part of a
larger keyboard, a touch screen, a mouse or track ball and
associated screen display, or any other input device
capable of performing a keypad function.
The invention can be expressed both as a method of
communicating an authentication code, and as a portable
display device to show an authentication code. The latter
can take many forms, but at its simplest, may be reduced to
a printed reminder card, in which the printing displays
images of an encoded form of an authentication code, the
CA 02333589 2000-11-28
WO 99/63492 PCT/GB99/01688
-4-
card being linked by the code to data in a data processing
machine.
According to one aspect of the invention, a method of
communicating an authentication code, comprising a
plurality of digits in sequence, to a data processing
machine, comprises: providing a data processing machine
with a terminal including a data entry keypad having a
plurality of keys corresponding to different digits
including the digits of the authentication code; providing
a portable display device adapted to display a sequence of
arrays of elements, each element of an array comprising a
different image of a human face; providing a concordance
between the respective elements of each array and
corresponding keys of the keypad; entering the consecutive
digits of the authentication code by selecting an image
from each array in sequence, identifying the element of the
array in which the selected image occurs, and actuating the
key corresponding to that element, whereby to communicate
the authentication code to the data processing machine.
According to another aspect of the invention, there is
provided a portable display device provided with means to
store and display an authentication code, consisting of a
plurality of digits in sequence, in encoded form to a user
of a data processing machine, wherein said data processing
machine is provided with a terminal including a data entry
keypad having a plurality of keys corresponding to
different digits including the digits of the authentication
code; said personal display device comprising means for
displaying a sequence of arrays of elements, each element
of an array comprising a different image of a human face,
wherein there is a concordance between the respective
elements of each array and corresponding keys of the
CA 02333589 2000-11-28
WO 99/63492 PCT/GB99/01688
-5-
keypad; so that by selecting an image from each array in
sequence, identifying the element of the array in which the
selected image occurs, and actuating the key corresponding
to that element, a user can enter the consecutive digits of
the authentication code and thereby communicate the code to
the data processing machine.
The concordance can be overtly expressed, or implicit in
the arrangement of the elements of the arrays.
In a further embodiment of the invention, the portable
display device is provided in combination with a mask and
with registration means for positioning the mask with
respect to the displayed sequence of arrays of elements, so
that, when the mask is registered with the arrays, the mask
identifies those images that correspond to the
authentication code. In this manner, the mask acts as a
key to reveal the images to be remembered by the user, and
to assist the user in memorizing the correct images.
The mask may be a perforated or at least partially
transparent overlay and may identify the images by exposing
them through apertures in the overlay or through
transparent portions of the overlay. A card supplier can
use such a mask to communicate the PIN to the user.
Alternatively, the portable display device can be combined
with a blank mask having a plurality of window portions
that are either temporarily occluded or transparent,
whereby a user can either clear selected occluded window
portions or mark selected transparent window portions to
make a mask to subsequently identify the images that
correspond to the authentication code. This is useful
where the user wishes to choose his own PIN. The occluded
window portions can be cleared by pressing them out of the
CA 02333589 2000-11-28
WO 99/63492 PCT/GB99/01688
-6-
mask, if they are delineated by perforations or scores, or
by locally peeling a removable latex or similar coating
from a transparent base, or transparent window portions can
be marked by ringing them round, or tinting them, with a
drawing or writing instrument such as a pen or the like.
Registration may make use of the edges of the card and of
the mask, and the mask may comprise an envelope dimensioned
to receive the device in a defined relative position.
In a still further embodiment, the invention provides the
combination of a portable display device as aforesaid and a
data processing unit provided with a terminal including a
data entry keypad having a plurality of keys corresponding
to different images including the digits of the
authentication code.
An embodiment of the invention is illustrated by way of
example in the accompanying drawings, in which
25
Figure 1 shows one face of a printed card, with an
insert indicating the numerical concordance between
the elements of each of four 3 x 3 arrays of faces and
the numeric keys of a keypad (not shown); and
Figure 2 illustrates a mask placed over the card of
Figure 1 in correct registration to show one image of
a human face from each of the four arrays.
As shown in Figure 1, four 3 x 3 arrays of nine images of
human faces each are imprinted on a standard credit card
sized card 6 and occupy between two thirds and three
quarters of the length of the card. This leaves blank
space 8 towards one end of the card for the electrical
CA 02333589 2000-11-28
WO 99/63492 PCT/GB99/01688
_7_
contacts, in the case of a smart card, and graphic
information including writing and promotional material (not
present in Fig 1). The sequence of arrays 1, 2, 3, 4,
corresponds to western writing, i.e. left to right, line by
line, starting at the top. The same sequence of images is
followed within each array of nine images, as illustrated
in insert A. The corresponding keypad may also appear as
in insert A, or may differ in appearance, but will have
means for entering the nine digits 1 to 9.
The card may be supplied with a cover 10 serving as a mask
(Figure 2) which when properly registered with the card 6
allows the user to see only four particular images through
four transparent window portions 11, 12, 13, 14, one from
each array, which in this case correspond to an existing
PIN number 4217 as defined by the concordance. That is to
say, image 4 in array 1, image 2 in array 2, image 1 in
array 3, and image 7 in array 4. The eight other window
portions in each array are occluded and hide the underlying
images. Alternatively, the user can choose a new PIN
according to which faces the user wants to use. In such a
case, the mask can be supplied to order with the chosen
faces showing, or the mask may be formed from a peelable
coating over a transparent base, so that the user can
scratch or peel the coating from the positions at which the
selected faces occur. In either case, when the user has
learned the key faces, the mask may be destroyed, leaving
only the card with its printed faces. An unauthorized user
cannot deduce the PIN from the imprinted card alone any
more easily than for an all-numeric code using the digits 1
to 9 without the presence of the faces on the card.
Registration is defined in this instance as the alignment
of the edges of the mask 10 with the edges of the card 6.
CA 02333589 2000-11-28
WO 99/63492 PCT/GB99101688
-8-
The mask may be a simple overlay, or may be an envelope for
the card.
All the faces shown in Figure 1 are different, and are
taken from both sexes. The faces can be as distinctive one
from another as desired. It is preferred that each image
is of a different face, rather than just a different image
of the same face.
It will be possible, but less secure, to use the same faces
in each of the four arrays, with only their positions
changed. The advantage is that the user only has to learn
to recognise one face. The disadvantage is that, once the
significance of the face is appreciated, it can be seen
that there are only 9 possible 4-digit codes, since any one
face can be traced through the sequence and defines the
start of a four digit code defined by the positions of that
same face in the subsequent three arrays.
The display of arrays of elements, each element comprising
a different image of a human face, may be a printed surface
in any convenient form, bearing the sequence of arrays
visibly imprinted thereon, and can of course be generated
by other means. However, the printed surface is currently
the preferred form, and can be on a separate card to be
stored apart from the identify card, benefit card, or other
device to which it relates. In the form of separate
printed cards or sheets, such display devices can be
collected together in the form of a book with multiple
pages, one for each different PIN of the user. Separate
display devices may also be printed in larger sizes than
standard credit cards, for the benefit of those with poor
eyesight. If not constrained by the size, shape or surface
features of a card, the number of arrays can easily be
CA 02333589 2000-11-28
WO 99/63492 PCT/GB99/01688
_g_
increased without losing visibility, to enhance the
security level.
A separate display device can be used and distributed as a
promotional gift.
The display of the faces serves as a PIN reminder to be
carried by the user without revealing that authentication
code to a third party.
