GB2433147A

GB2433147A - A method for verifying a person's identity or entitlement using one-time transaction codes

Info

Publication number: GB2433147A
Application number: GB0613835A
Authority: GB
Inventors: Jonathan Geoffrey Milt Craymer; Stephen Andrew Howes
Original assignee: Individual
Current assignee: Individual
Priority date: 2005-12-01
Filing date: 2006-07-13
Publication date: 2007-06-13
Also published as: GB0613835D0

Abstract

A method for verifying a person's identity is of the general type which comprises storing a personal pattern of a pre-determined number of locations on a grid in association with personal identification data, and subsequently using the pattern in a verification process. According to the invention, the subsequent verification process comprises the steps of: <SL> <LI>(a) presenting to the person a challenge grid of locations occupied by a pseudo-random set of symbols such as numbers, and challenging the person to identify a response set of symbols occupying locations in the challenge grid corresponding to the stored personal pattern; <LI>(b) receiving from the person the response set;(c) generating from the challenge grid and the stored pattern a verification set of symbols occupying locations in the challenge grid corresponding to the stored personal pattern; <LI>(d) comparing the response set of symbols with the verification set of symbols; and <LI>(e) verifying the identity of the person if the response set is the same as the verification set. </SL>

Description

Printed: 05-09-2006 DESC 0613835 A METHOD AND APPARATUS FOR VERIFYING A

PERSON'S IDENTITY OR

ENTITLEMENT USING ONE-TIME TRANSACTION CODES

Field of the Invention

The present invention relates to a method and apparatus for verifying a person's identity or a person's entitlement, e.g. to access premises or to obtain certain services.

Background to the Invention

Credit card fraud is a major problem to retailers and credit card compa-nies alike. Many credit card companies have addressed this problem with the introduction of Chip and Pin' technologies but this does not address the prob-lem of Card not present' fraud which is on the increase as more people make on-line credit card purchases or purchase goods by telephone.

Furthermore, with the prevalence of computer viruses and in particular Trojans' which capture keystrokes (including credit card and personal identifica- tion numbers (uPlNs)) sending credit card information and PINs to an un-trusted second party is inherently insecure.

The present invention provides a method by which fraud can be reduced through the use of one-time' transaction codes, as well as providing a general means of validating someone's identity or entitlement.

Potential uses include Credit card purchases, premise and vehicle entry systems (including vehicle ignition switching), bank customer verification, pass-port verification, a replacement for passwords, or in any other situation where a person's entitlement to service' is required.

In US-B-6 246 769 there is disclosed a system for replacing PINs with a transaction specific code which the user identifies from a matrix of symbols by reference to a personal randomly chosen pattern and sequence of matrix posi- tions which the user registers with a central database along with personal identi-fication data/account data. When a transaction, for example, is to be made, the user's pattern is retrieved from the database, and the transaction specific code is created and then placed in a matrix in the pattern positions. The remaining spaces are filled with symbols not used in the transaction specific code, to hide the code, before the matrix is displayed to the user with a request to enter the 13-07-2006 SpeciIicaon CRAYMEJP1344.GBA3-2006-07-12 Printed: 05-09-2006 DESC 0613835 symbols occupying the user's personal pattern positions. The terminal then es- tablishes that the user has entered the correct hidden code before seeking au-thorisation of the transaction.

In many situations, this process is undesirable for two principal reasons.

Firstly, it requires the transmission of the user's stored personal pattern from the central database to the user terminal (ATM, for example), which is potentially insecure, and secondly the transaction requires either two separate data calls to the central database, or one continuous connection for the duration of the trans-action. In either case, this is unacceptable for shop or bank transactions, as it would considerably increase the cost of operating the system -such transac- tions preferably only involve one brief communication to obtain authorisation for the transaction -while possibly increasing the risk of a breach of transaction se- curity if the authorisation process required a continuous connection for the dura-tion of the transaction.

Summary of the Invention

The present invention provides a method for verifying a person's identity, comprising storing a personal pattern of a number of locations on a grid in as-sociation with personal identification data, and subsequently using the pattern in a verification process, wherein the subsequent verification process comprises the steps of: (a) presenting to the person a challenge grid of locations occupied by a pseudo-random set of symbols, and challenging the person to identify a re-sponse set of symbols occupying locations in the challenge grid corresponding to the stored personal pattern; (b) receiving from the person the response set; (c) generating from the challenge grid and the stored pattern a verifica-tion set of symbols occupying locations in the challenge grid corresponding to the stored personal pattern; (d) comparing the response set of symbols with the verification set of symbols; and (e) verifying the identity of the person if the response set is the same as the verification set.

2 13-07-2006 SpeciIicaon CRAYMEJP1344.GBA3-2OO6-O7-12 Printed: 05-09-2006 DESC 0613835 Preferably, the registration step comprises first providing the person with a grid and inviting the person to select the personal pattern of locations. The invitation may be to select a pre-determined number of locations to form the personal pattern, or to select a length of pattern from one of several pre-determined numbers, for example 4, 5 or 6, or even to select as many locations as the person feels able to remember reliably, subject to a minimum number.

In one aspect of the invention, the method comprises communicating the identified symbols to a transaction authorising computer at a location remote from the person and conducting steps (b) to (e) in said authorising computer.

According to one embodiment of the invention, step (a) comprises gen-erating the challenge grid in a user terminal and transmitting to the authorising computer the verification set of symbols and the challenge grid or data enabling the authorising computer to identify or recreate the challenge grid. Preferably this embodiment comprises using an algorithm in the user terminal to generate a pseudo-random string of symbols according to the date and/or time of day and identity data for the terminal and/or the person to construct the challenge grid, and transmitting to the authorising computer at least the verification set of symbols and identity data, the authorising computer using the same algorithm and said identity data and the date and/or time of day to generate the same pseudo-random string of symbols, thereby to recreate the challenge grid. Fur-ther security can be achieved in this method by using a second algorithm to generate from the verification set and at least one factor from: (i) the transaction time and/or date; (ii) a personal or account identifier; (iii) a terminal identifier; and (iv) a public/private data key; a token consisting of a string of symbols concealing the verification set, and wherein the step (c) comprises using the recreated challenge grid to gener-ate the verification set, applying the second algorithm using the factor or factors to generate a token from the verification set, and step (d) comprises comparing the received token with the generated token.

3 13-07-2006 SpeciIicaon CRAYMEJ-P1344.GBA3-2OO6 07 12 Printed: 05-09-2006 DESC 0613835 According to another embodiment of the invention, step (a) comprises algorithmically selecting in a user terminal one of a plurality of challenge grids previously supplied to said user terminal by a transaction authorising body or the transaction authorising computer and stored in the terminal, and transmitting to the transaction authorising computer the verification set of symbols and data identifying to the authorising computer the algorithmically selected grid.

In another embodiment of the invention, step (a) comprises algorithmi-cally selecting in a user terminal a start reference point in a large matrix of sym-bols previously supplied to said user terminal by a transaction authorising body or the transaction authorising computer and stored in the terminal, presenting a challenge grid derived from the large matrix using the start reference point, and then transmitting to the authorising computer the verification set of symbols and the start reference point.

In a further embodiment of the invention, step (a) comprises algorithmi-cally selecting in a user terminal a predetermined number of symbols from a large matrix of symbols previously supplied to said user terminal by a transac-tion authorising body or the transaction authorising computer and stored in the terminal, presenting a challenge grid of said selected symbols, and then trans-mitting to the authorising computer the verification set of symbols, and wherein in step (C) the authorising computer applies the same algorithm to select from the large matrix previously supplied the same symbols to reconstruct the chal-lenge grid.

In another alternative embodiment of the invention, step (a) comprises receiving in a user terminal a start reference point transmitted thereto by the authorising computer, the start reference point indicating a position in a large matrix of symbols previously supplied to said user terminal by an authorising body or the authorising computer and stored in the terminal, presenting a chal-lenge grid derived from the large matrix using the start reference point, and then transmitting to the authorising computer the verification set of symbols.

In a still further embodiment of the invention, step (a) comprises retriev- ing from a database of grids independent of the authorising computer an algo-rithmically selected one of a plurality of grids stored in said database, said grid 4 13-07-2006 SpeciFicaon CRAYMEJP1344.GBA3 2006 0712 Printed: 05-09-2006 DESC 0613835 having a unique identifier, and transmitting to the authorising computer the veri-fication set of symbols and said grid identifier, and step (C) comprises the authorising computer transmitting the identifier to the independent database to retrieve the challenge grid.

Access to a computer or other equipment could be controlled according to the method of the invention.

The grid may be pre-printed with a plurality of symbols in respective grid positions.

In one embodiment, the invention comprises a method for identity verifi-cation or service entitlement' which may (but is not necessarily a requirement) be used in conjunction with a device for recording securely any codes or PINs or the like. In particular, the present invention may be used in concert with the Craymer Grid', which is the subject of copending Patent application No GBO51 7333.1.

The Craymer Grid is a device for the secure storage of information and comprises a first member having a first surface, a second member having a second surface, the first and second members being moveable relative to one another to a selected position, the first surface having at least one window therein so that parts of the second surface are visible through the at least one window, and the first and second surfaces are provided with grid markings into which a user may write indicia, such that predetermined indicia on the second surface are only visible through the at least one window when the first and sec-ond members are in the selected position. The device may be in the form of a flat sleeve containing a slidable member marked with an empty grid pattern onto which the user may enter one or more PIN codes or other security digits, letters or both. When this is done, the user can fill the remaining grid positions with random digits, letters etc. When the user wants to use a particular PIN code (say) he/she moves the member inside the sleeve until the desired code ap-pears in the window. Only the user knows what that position is. The user may mark the grid in a secure way to remind himself what the start position' is to enable the user to read the proper code.

13-07-2006 Speciticaon CRAYMEJP1344.GBA32Oo6 07 12 Printed: 05-09-2006 DESC 0613835 It will be understood that the use of the term "grid" herein encompasses not only regular grids as hereinafter described with reference to the drawings, but also irregular arrangements of locations. For example, locations on the "grid" could be represented by different elements of a picture, and the spacing of one location relative to any other does not need to be uniform, either in dis-tance or direction.

Alternatively, the invention may use virtual grids held on credit or debit (or other personally-identifying) card chips, i.e. the virtual grid is represented by data that can be expressed to the user as a grid by a card reading device.

These may be read at an EPOS or by a dedicated card reader or a telephone, such as a mobile phone, which may be fitted with a card reader, or any other suitable electronic device. The grids may alternatively be held (as virtual grids) on the telephone. An EPOS may generate its own grid. The user's chosen pat-tern could be securely saved on the card chip, for example.

Alternatively, the invention may use grids that are generated automati-cally by the authenticator, with the verification made by comparing the user's response to a pre-registered pattern that the authenticator has securely en- coded on to the user's credit/debit card chip or other identity or entitlement de-vice.

The method of the present invention requires that the party (authentica- tor) who is wishing to make the verification (e.g. credit/debit card company) is- sues a challenge to the user (e.g. purchaser) for a set of numbers (authentica- tion code) based on a grid that the authenticator generates or by a grid refer-ence' specified by the authenticator.

The user then uses a grid of numbers which is also known by the authen-ticator (e.g. Craymer Grid or an on-line grid presented on-screen which has been generated by the authenticator) and picks a set of numbers according to a pattern or shape' known only by himself and the authenticator and then com-municates these numbers back to the authenticator.

Since the authenticator also knows the grid numbers and the user's known sequence and pattern he can also look up the same sequence and pat-tern of numbers and, if they match, they have a positive verification.

6 13-07-2006 Specilicalion CRAYMEJ-P1344.GBA3---2006-07 12 Printed: 05-09-2006 DESC 0613835 Since the authenticator may ask for a sequence and pattern of numbers based on a random home or grid-reference, subsequent transactions are likely to require that the user start from a different grid reference position. This will mean that on subsequent transactions a different authentication code will be required. (This situation will typically arise when a user is using an off-line, rather than an on-line, grid.) It will be understood that references to a uset of numbers" and the like in-clude symbols other than Arabic numerals.

The invention also provides apparatus for use in verifying a person's identity, comprising means for receiving and storing identification data for the person and a linked pattern chosen by the person (or possibly allocated initially by the authorising body) of locations on a grid, electronic means at the person's location for presenting to the person a challenge grid and an invitation to the person to identify in response thereto symbols occupying locations in the chal-lenge grid corresponding to the stored personal pattern, and verification means for receiving from the person the response set, the verification means being ar-ranged to generate from the challenge grid and the stored pattern a verification set of symbols occupying locations in the challenge grid corresponding to the stored personal pattern, to compare the response set of symbols with the verifi-cation set of symbols, and to verify the identity of the person if the response set is the same as the verification set.

The verification means may comprise a transaction authorising com-puter.

The electronic means is suitably a user terminal remote from the transac-tion authorising computer.

In one embodiment of the invention, the user terminal is programmed to generate the challenge grid, and arranged to transmit to the transaction author-ising computer at a location remote from said user terminal the verification set of symbols and the challenge grid or data enabling the transaction authorising computer to identify or recreate the challenge grid.

In another embodiment, the user terminal is programmed to use an algo-rithm to generate a pseudo-random string of symbols according to the date 7 13-07-2006 SpeciIicationCRAYMEJP1344.GBA3-2006 07 12 Printed: 05-09-2006 DESC 0613835 and/or time of day and identity data for the terminal and/or the person to con-struct the challenge grid, and arranged to transmit to the transaction authorising computer at least the identity data, and wherein the transaction authorising computer is programmed to use said identity data and the date/time of day to generate, using the same algorithm, the same pseudo-random string of sym-bols, thereby to recreate the challenge grid. The user terminal may further be programmed to use a second algorithm to generate from the verification set and at least one factor from: (i) the transaction time and/or date; (ii) a personal or account identifier; (iii) a terminal identifier; and (iv) a public/private data key; a token consisting of a string of symbols concealing the verification set, and the transaction authorising computer is programmed to use the recreated challenge grid to generate the verification set of symbols, to apply the second algorithm using the factor or factors to generate a token from the verification set, and then comparing the received token with the generated token to estab-lish or deny verification.

In another embodiment, the user terminal is programmed to select algo-rithmically one of a plurality of challenge grids previously supplied to said user terminal and stored therein, and arranged to transmit to the authorising com-puter the verification set of symbols and data identifying the selected grid.

In yet another embodiment, the user terminal is programmed to select algorithmically a start reference point in a large matrix of symbols previously supplied to said user terminal and stored therein, to present a challenge grid derived from the large matrix using the start reference point, and then to trans-mit to the authorising computer the identified symbols and the start reference point.

In another embodiment, wherein the user terminal is programmed to Se-lect algorithmically a predetermined number of symbols from a large matrix of symbols previously supplied to said user terminal by a transaction authorising body or the transaction authorising computer and stored in the terminal, to pre- 8 13-07-2006 SpeciIicaon CRAYMEJ-P1 344.GBA3 -2OO6 07 12 Printed: 05-09-2006 DESC 0613835 sent a challenge grid of said selected symbols, and then to transmit to the authorising computer the verification set of symbols, and wherein the authoris-ing computer is programmed to apply the same algorithm to select from the large matrix previously supplied the same symbols to reconstruct the challenge grid.

In a further embodiment, the user terminal is programmed to receive a start reference point transmitted thereto by the verification computer, the start reference point indicating a position in a large matrix of symbols previously sup- plied to said user terminal and stored therein, to present a challenge grid de-rived from the large matrix using the start reference point, and then to transmit to the transaction authorising computer at a location remote from the user ter-minal the identified symbols.

In a still further embodiment, the user terminal is programmed to retrieve from a database of grids independent of the transaction authorising computer and of the person an algorithmically selected one of a plurality of grids stored in said database, said grid having a unique identifier, and to transmit to the trans-action authorising computer at a location remote from the user terminal the identified symbols and said grid identifier, and wherein the transaction authoris- ing computer is programmed to transmit the identifier to the independent data-base to retrieve the challenge grid.

The user terminal may be an automated teller machine (ATM). Alterna-tively, the user terminal is a computer connectible to the authorising computer via a network connection, or a portable electronic device connectible to the authorising computer through a wireless connection.

In the case where the challenge grid is calculated algorithmically, the user's device can be completely separate from the authentication computer. In this case, the verification symbols may, for example, be communicated verbally to a third party telesales operator who completes the verification step, or via voice recognition software.

Advantages of the invention include the following: People find it difficult to remember PINs. However, the human mind is much better at remembering shapes and patterns. This method eliminates the 9 13-07-2006 SpeciFicaonCRAYMEJP1344.GBA3--2O06 0712 Printed: 05-09-2006 DESC 0613835 need to remember PINs. This provides a higher degree of security than exists at present whilst providing the user with a simpler way of remembering their au-thentication means.

Due to the randomness of the grid challenge, the correct authentication code will change on subsequent transactions. Therefore in the case of a credit card purchase, if someone sees the user entering a transaction code and sub-sequently steals the credit/debit card then the PIN/credit card will be useless to him unless he knows the user's chosen sequence' and pattern'.

People often compromise the security of their credit/debit cards by writ-ing down their PINs. The abstract nature of patterns proposed in the method of this invention makes it more difficult for the pattern to be written down or de-scribed'.

Since the transaction codes change on a per-transaction basis it is pos-sible to make relatively secure on-line transactions over the internet or over the telephone. Transaction verification may also be made using a portable elec-tronic device, particularly a communications device such as a smart' telephone, i.e. a mobile telephone equipped with a card reader, or a less capable mobile telephone, as will be described later in this specification.

Most authentication systems ask for a four digit PIN. However, since people find patterns easier to remember than numbers, it is possible to intro-duce 5, 6 or more digit authentication codes without undue problems for the user.

The method could potentially be used without any additional hardware in-frastructure at Point of Sale terminals, for on-line web purchases or at AIMs.

Such terminals may be provided by smart telephones, as described later. It is envisaged that existing Chip and Pin' hardware could be used albeit with some minimal software reprogramming.

For credit/debit card purchases, more than one credit/debit card could be registered for use with a number grid.

The process is easily learnt and does not require a high degree of so-phistication on behalf of the user.

Braille systems could easily be produced for sight-impaired people.

13-07-2006 SpeciIicaoi1CRAYMEJ-P1344.GBA32OO6-O7 12 Printed: 05-09-2006 DESC 0613835 -11 - For on-line or other electronic purchases, no additional hardware is re-quired by the user. For other situations where a paper-based grid is required, the user hardware required is cheap to produce and is of little or no value if sto-len.

The security is only compromised if a third party knows the sequence' and the pattern'. A casual or even a malevolent observer would not easily as-certain it.

Importantly, the system does not at any stage transmit the actual per-sonal pattern, nor does it use that pattern in the construction of the challenge grid, and so the risk of this being intercepted and misused by a third party is avoided. Furthermore, the system enables an authorisation for a transaction, for example in an ATM or POS machine, to be obtained securely with a single short connection to the authorising computer, keeping communication costs to a minimum and increasing security for the communication. This is particularly im-portant where the communication is made with the authorising computer via a modem and dial-up connection, which is currently the standard method. Each resulting telephone call may involve a cost, as well as taking time to establish the connection, and telephone calls are also commonly charged for according to the duration of the call, so remaining connected for the duration of the transac-tion could substantially increase costs, especially when some users are slower in completing transactions than others.

While the invention is important for authenticating individuals to an or-ganisation such as a bank, it also provides the possibility of the bank or other organisation proving its authenticity to the user. This might be important to overcome the fraudulent technique known as "phishing", where people are in-duced to disclose confidential account information through fake bank internet sites, this information then be used to steal money from the individual's bank account. In order to demonstrate to the user that a bank internet site is genu-ine, it would be possible to use the two secret pieces of information shared by the bank and the user, under the method of the invention, namely a standard PIN and the user's secret pattern. Before disclosing any confidential data (such as a login password) on the bank internet site, the user needs reassurance that 11 13-07-2006 SpeciIicaonCRAYMEJ-P1344.GBA3--2006 0712 Printed: 05-09-2006 DESC 0613835 the site is genuine. This could be provided by the bank's site displaying, in re-sponse, say, to the user's name being entered, a grid full of random (or at least pseudo-random) numbers, except that the user's PIN is displayed in the user's secret pattern positions. The user can check that these are correct before pro-ceeding with the usual security input to gain access to the site.

Brief Description of the Drawings

The invention will be described with reference to the accompanying drawings, of which: Figures 1 to 3 illustrate a grid and different methods of using the grid in accordance with the invention; Figure 4 illustrates a variation on the grid; Figure 5 illustrates a variety of tessellations that could be used for the grid; Figure 6 is a flow chart illustrating a method for online verification accord-ing to one embodiment of the invention; Figure 7 is a flow chart illustrating a method for online verification using an external database of standard challenge grids; Figure 8 is a flow chart illustrating a method for verification where a sin-gle large grid is employed, the user being directed to a particular location on the grid as a starting reference point; Figure 9 is a flow chart illustrating a method for verification using a grid generated locally by a time-dependent algorithm; Figure 10 illustrates apparatus for verification of a transaction according to another embodiment of the invention; Figure 11 illustrates a variant of the apparatus of Figure 10, using an ex- ternal database of standard challenge grids, for example as in the method illus-trated in Figure 7; Figure 12 illustrates a variant on the apparatus of Figure 10, using a cel-lular telephone as the verification user terminal; and Figure 13 is a flow chart illustrating a method of verification according to yet another embodiment of the invention.

12 13-07-2006 SpeciIicaon CRAYMEJ-P1344GBA3-2QQ6-O7 12 Printed: 05-09-2006 DESC 0613835 Detailed Description of the Illustrated Embodiments As an aid to understanding the following description, we use the following terms: Grid' -A tabulated set of symbols, such as numbers or letters or a corn-bination of both. This grid may be (but need not necessarily be) represented on a Craymer Grid' forming the subject of our above referenced co-pending patent application.

Pattern' -A choice of grid positions which make up a pattern' which is only known by the user of the grid and the authenticator (see below). A pattern is not necessarily a naturally recognisable shape such as a straight line, square or triangle. Indeed, it is preferable for it not to be a regular shape. Sequence' -The order in which the grid positions in a pattern' are

se-lected.

Authenticator' -A person or organisation who wishes to check some-one's identity or entitlement.

User' -A person or organisation that is using the system and needs to validate his/its own identity or credentials.

Operation of the Method The method in accordance with the invention comprises the following component stages, which are dependent on whether the user uses the method electronically (e.g. by telephone or on-line) or manually (e.g. using a paper grid made available to the user).

1. Registration (including the following three actions): A. Issuing of hand-held grids (which is not necessary for on-line au-thentication) B. Registering the hand-held grid (which is not necessary for on-line authentication) C. Registering a sequence and pattern (which is required for both hand-held grids and on-line authentication) 2. Using the system with a hand-held grid.

OR

13 13-07-2006 SpeciricaborCRAYMEJ-P1344.GBA3--2CO6 07 12 Printed: 05-09-2006 DESC 0613835 3. Using the system with an electronic grid (e.g. for on-line purchases or at an ATM).

The various stages will now be described in more detail.

1. Registration a. Issuing Grids When using the hand-held version of the method, it is necessary that a pre-printed grid be issued to the user. For large scale use (e.g. by a credit/debit card company), they may choose to print many millions of different grids in or- der to reduce the chances of two people having the same grid. It is not neces-sary that each person has a unique grid; however, the more variations of a grid there are the more the security is enhanced. The grids will need to display row and column identifiers, for example letters for columns and numbers for rows.

The identifiers could alternatively or additionally be symbols, colours, or combi-nations of these.

The grids are of the same size and format as one another but the ar-rangement of symbols (digits, letters etc) will vary from one grid to the other.

However, it is possible for the method to operate successfully and securely if the same symbols are printed on every grid because each user will select a dif-ferent pattern and sequence for his own identity or entitlement.

Each grid will carry an identification code which will uniquely identify the grid. This ID would be stored in a secure computer database along with the user's details and an electronic copy of the grid's numbers. The identification number should not in any way give any clues as to the numbers on the grid.

b. Registering hand-held grids Users will be required to acknowledge that they have received the Grid and to register the grid as belonging to them. Each card issuer (e.g. bank) will have its own preferred method of issuing the grids and identifying the end-user depending upon their desired level of security. Examples of how this could be done include face-to-face registration, On-line registration or Automated Tele-phone registration.

14 13-07-2006 SpeciIicaonCRAYMEJP1344.GBA3-2006 0712 Printed: 05-09-2006 DESC 0613835 A card issuing agency could be a trusted authentication agency to which many organisations could subscribe. For example a trusted agency could rep-resent several credit card companies.

Registering a Pattern/Sequence Once the identity of the user is known to the authenticator the user will need to register his own personal sequence and pattern'. This will be a key or shared secret' which only the user and authenticator will know.

A specific method for registering a pattern on-line is shown in Figure 1.

The user is presented with a grid of squares. Figure 1 shows a 7x7 grid which will provide a good degree of security for such things as credit card purchases.

However, the grid could be made larger for greater security or smaller for lesser security, but greater convenience of use.

The centre of the grid (A), Figure 1, is known as the home' or grid refer-ence point' around which the user will need to select their pattern. The grid may be marked in colour to make it easier for the user to navigate round the grid but colours or shading etc are not necessary.

The user would normally be asked by the authenticator to create a pat-tern of four positions, i.e. the equivalent security level of a standard PIN. As-suming that this process is being conducted electronically, the user would click on the appropriate squares in sequence. As he does so the selected squares could be illustrated, e.g. by illumination, the appearance of the symbol itself, or perhaps by a single symbol, such as a * in each position. (The user may be asked for more or fewer grid positions depending upon the degree of security required).

The example shown here shows that the chosen pattern sequence is (1) diagonally above and to the left of the grid reference point. The second position (2) is to the left of the reference point, the third (3) is to the left of the second and the fourth (4) is below the second. It will, of course, be critical to authenti- cation in most applications that the correct pattern is described in the right Se-quence. This is of course no different to requiring the characters of a PIN to be entered in the proper sequence, otherwise the incorrect sequence will be re-jected, even though the characters may be the same. It should be pointed out, 13-07-2006 SpecifIcabonCRAYMEJP1344.GBA32OO6 07 12 Printed: 05-09-2006 DESC 0613835 however, that a low-security application could be based on identification of the correct pattern without regard to the sequence.

When choosing a pattern the user should be encouraged to be as devi-ous' as possible and should be discouraged (and potentially prohibited) from picking straight lines or other obvious shapes. Similarly, they should not neces-sarily believe that they have to use the grid reference point in their selection.

The pattern can be anywhere on the grid, and the individual elements of the pattern need not be adjacent to each other or even in the same region of the grid. In essence, the more obscure the pattern, the more secure their pattern will be. There is no reason why a square could not be chosen more than once.

However, from a security perspective, it is unlikely that an authenticator would want to allow the user to select the same number four times, for example.

Clearly on a 7x7 grid there are a multitude of possible patterns that a user can select. It is informative to note that there are approximately 5.7 million patterns for a 4-position code rising to approximately 282.5 million for a 5- position code. The grid positions chosen by the user need not be touching, ei-ther along sides or at corners.

If the user is registering a standard Craymer Grid' then they will addi-tionally need to enter their selected start position' and the preferred card side (grey or black). This becomes part of the key or shared secret' between user and authenticator.

If the system is being used in conjunction with, for example, a credit/debit card, the authenticator may at this stage want to associate the card with the person's registration. This will be necessary in instances where the user may want to make Card not present' purchases. This could be done by swiping the card or by doing a standard chip and pin authentication to associate the card number with the user.

As well as an on-line' method of registering a pattern, it is also possible to register by telephone or verbally by giving each grid position a number from say 1 to 49 (for a 7 x 7 grid). The precise method used will be dependent on the desired level of security. For example, a bank may require a person use 16 13-07-2006 SpeciIicaonCRAYMEJP1344.GBA320O6 0712 Printed: 05-09-2006 DESC 0613835 their e-banking facility to register a sequence and pattern or to go in person to the branch to enter it.

An alternative approach in the registration of the pattern would be for the authenticator to fill the registration grid with non-repeating characters arranged randomly. For example, for a 5 x 5 grid, the letters A to Y could be used with no repeats. The user can then indicate to the authenticator his chosen pattern by entering the letters in the chosen squares. As these are non-repeating, the au-thenticator can readily identify the pattern/sequence.

2. Using the system with a hand-held grid (e.g. Craymer Grid) To use the grid it is necessary that the grid be registered to a user and that the user has registered a pattern and (usually) sequence with the registra-tion agency (authenticator, credit/debit card company etc) as just described.

To illustrate the process, an over-the-counter credit card purchase will be used as an example, in which the following steps occur: a) The customer selects some goods and goes to the store checkout to pay for them by credit/debit card as normal.

b) He hands over his card as normal and it is placed in a Chip and PIN' device.

c) Instead of being asked for a PIN, he is asked to enter four digits corresponding to a randomly selected grid reference (e.g. G4) on his pre-viously registered grid. The home or grid reference position is randomly or algorithmically chosen by the credit card agency.

d) A typical grid is shown in Figure4, consisting of columns identified by letters A to 0 and rows identified by numbers 1 to 12. Of course, other combinations are equally acceptable. The number of rows and/or columns can be varied according to the desired level of security. A grid position can therefore be located by a unique number/letter combination.

However, a Craymer Grid' could provide a higher level of security.

e) Using the example above and the example pattern shown during the registration process (Figure 2), the user would find grid position G4 (in this case the number 0) and use this as his grid reference point.

17 13-07-2006

Specification CRAYMEJ-P1344.GBA3 2OO8-O7 12

Printed: 05-09-2006 DESC 0613835 f) Having found position G4 and remembering his sequence and pattern, the user will enter the four digits that he sees associated with his pre-registered pattern. (See figure 2). So, in this example the numbers will be "9846".

g) He will then enter those four digits onto the chip and pin' keypad.

h) The credit card company's computer system will then check those four digits against the grid associated with his credit card and with the pre-selected sequence and pattern.

i) If these digits match, then the user is verified and the transaction is completed.

The next time the user makes a purchase, the credit card agency will randomly or algorithmically pick a new grid reference' position, and therefore the four digit code required to authenticate the transaction will be different. For example on the next transaction the user may be asked for a number corre-sponding to "K9" then the valid code would be "9047".

It is not entirely necessary that the person uses his own grid for the transaction. He could use any registered grid (e.g. a grid registered to the shopkeeper or to a friend). In this case the alternative grid ID will need to be entered at the point of sale prior to the user entering his transaction code. This variation to the process means that the user can still use the system without the need to carry his own card. This has particular advantages if for example a per-son has his credit card and grid card stolen. In this situation the user could telephone the authentication agency and identify himself by, for example name and address, and then the agency asks for authentication by use of a third party's grid.

Whilst this does not provide the same high level of security, in the ab- sence of any other form of identification it is better than nothing. It could there-fore be used adequately for example in low value' transactions where there is a low risk.

There now follows a description of a further example of how the invention can be used to buy goods or services, e.g. theatre tickets, over the telephone.

18 13-07-2006 SpeciuicaonCRAYMEJ-P1344.GBA3--20O6 0712 Printed: 05-09-2006 DESC 0613835 The user will speak to the booking agent who will then ask for the credit card number. The agent will then validate the credit card and then the credit card company will ask the operator to ask the customer to provide a transaction code based on a grid reference that the credit card company specifies.

The agent will then ask the user for the transaction code over the tele-phone, the user will then find the transaction code numbers using his grid and read them out to the agent.

The agent will then enter the numbers and the credit/debit card agency will either accept or reject the transaction.

This process is far more secure than exists at present as it does not re- quire the booking agent to be trusted. Even if the agent remembers the transac-tion code and credit card number it will serve no useful benefit to him if he fraudulently tries to make another transaction because next time a different transaction code will be asked for.

This method will also be of use to disabled people who have a carer, for example a stroke patient who may have difficulty speaking on the telephone or using a chip and PIN keypad, but who could use the grid. In this way, the dis-abled user could tell the carer the transaction code, and this could be safely communicated to the company concerned by telephone or typed in. So long as the disabled user keeps his grid and pattern safe, his transactions are secure.

3. Using the system with an electronic arid (e.g. for on-line rurchases over the web, at an ATM or at a Point of Sale Terminal) For on-line authentication (e.g. on-line purchases) there are three van-ants of how the invention could be used. The choice of method is very much dependent upon the perceived security risk and desired level of convenience.

The three methods are: By using a registered paper grid as illustrated in the example above.

By using an electronic one-time' grid in the same form as shown above (Fig 4) or by using an electronic "Craymer Grid" By using a simplified one-time' electronic grid in the form illustrated in Figure 3.

19 13-07-2006 SpeciIicaonCRAYMEJ-P1344.GBA3-2OO6 0712 Printed: 05-09-2006 DESC 0613835 -20 -In such an instance as this, the user would be shown a grid in the form shown in Figure 3. However, the numbers displayed will be algorithmically gen- erated by the authentication system. The authentication system will secretly re-member' the grid numbers until the transaction is complete.

The user will then select his number pattern by either clicking on the ap- propriate squares, touching a touch screen, or preferably by entering the asso-ciated numbers on the keypad, since someone looking over his shoulder might be able to see the pattern being entered, and similarly, it might be possible for the clicking on the squares to be monitored illegally remotely. Entering the numbers does not give away the pattern, because the same number will repre-sent many different patterns. The only time someone should be allowed to click on squares connected with the pattern is when they are registering the pattern, and it is expected that the user will do this safely.

Using the example from Figure 2, the authentication code in this instance would be "5178". Once entered, the authenticator will then check the digits en- tered against its known pattern and sequence and, if they match, the user is au-thenticated.

There are various advantages in using an electronic grid in this form: a. Anyone eavesdropping the keystrokes on the computer will see the digits being entered but since the transaction code is one-time' this will not benefit him for any further transactions.

b. Even if an eavesdropper can detect the numbers on the screen (which may be very difficult if the numbers are displayed as a graphic) then he still may not be able to determine the user's sequence and pat- tern' even if the eavesdropper detects the keystrokes. Since in this ex-ample the digits "5178" appear multiple times in the example grid, the eavesdropper would potentially need to observe several transactions in order to obtain enough clues' by which he can determine the pattern.

c. Clearly, the more devious the user at selecting a pattern, the more difficult it would be for any eavesdropper to determine the pattern.

13-07-2006 SpeciIicaonCRAYMEJP1344.GBA3-2006 0712 Printed: 05-09-2006 DESC 0613835 -21 -Usinci the system with mobile teleDhones The present invention may be used with mobile telephones in a variety of ways, depending on whether or not the mobile telephone is provided with a card-reading capability (i.e. a smart phone').

Where the phone incorporates a card reader, essentially it becomes a personal EPOS system in itself. First, the user would insert his/her card into the phone (just like EPOS terminals in shops). The authenticating computer would then send a 7 x 7 (for example, or 5 X 5) grid to the screen of the phone. The user would, using the system of pattern and sequence central to the present in-vention, identify the digits required by the authenticating computer to answer its challenge, and input them into the mobile phone key-pad, completing the trans-action authentication.

For less-capable mobile phones a software application would be written and securely downloaded onto the phone (in the same way as perhaps a ring tone) that would store a number of virtual grids of numbers. In a similar fashion to the paper grid, the authentication system would challenge the user with a grid reference, but instead of something like G4' it would make the challenge with a grid number e.g. "234". The user will type 234 into his phone and the phone would then display the standard grid of the type described with reference to Fig-ure 3 on the LCD display. The user would then use this in exactly the same way as the on-line system. The credit/debit card-issuing company could auto- matically provide the user with a new set of grids via GPRS or SMS on a peri-odic basis, say weekly or monthly.

Alternatively, the mobile telephone could generate a challenge grid algo-rithmically and therefore independently of the authenticating computer.

It should be emphasised here that the current preferred form of the sys-tem of the invention depends on a unique combination of pattern and sequence, providing a personal identification pattern (PIP) unique to an individual user.

Further, it should also be emphasised that the use of grids containing only squares or rectangles, as disclosed so far, is not the only option. In fact, any tessellated shapes may be used. Thus, a regular polygon has 3 or 4 or 5 or more sides and angles, all equal. A regular tessellation is a tessellation made 21 13-07-2006 Specificaon CRAYMEJ-P1344.GBA3 -200607 12 Printed: 05-09-2006 DESC 0613835 -22 -up of congruent regular polygons._ For all practical purposes, only three regular polygons tessellate in the Euclidean plane, namely triangles, squares and hexa- gons. Figure 5 shows examples of tessellated triangles, squares and hexa-gons. It can readily be seen from these examples that the squares are lined up with each other while the triangles and hexagons are not. Also, if six triangles form a hexagon, the tiling of triangles and the tiling of hexagons are similar and they cannot be formed by directly lining up shapes under one another -a slide (or a glide) is involved. Being regular shapes, they could readily be used as a reference grid for a user to select his or her unique pattern and sequence.

There is a naming scheme by which tessellations are identified. Thus, a tessellation of squares is named "4.4.4.4". This is derived by selecting a vertex and then looking at one of the polygons that touches that vertex and deciding how many sides it has. Since it is a square, it has four sides, leading to the first "4". _Repeating the exercise by going around the vertex in either direction, and finding the number of sides of the polygons until you get back to the polygon you started with leads to a count of the number of polygons counted. In the case of squares, there are four polygons and each has four sides. The final "name" is therefore 4.4.4.4, as shown in Figure 5.

The identification for a tessellation of regular congruent hexagons is 6.6.6 and that for a tessellation of triangles is 3.3.3.3.3.3, since each triangle has six polygons surrounding a vertex and each has three sides._ However, the invention also contemplates the use of semi-regular tessellations, which consist of a formation of regular polygons with an identical arrangement of regular poly- gons at every vertex. Examples of semi-regular tessellations are shown in Fig-ure 5, using a mixture of squares and triangles (3.3.3.4.4 or 3.3.4.3.4), squares, triangles and hexagons (3.4.6.4); triangles and hexagons (3.6.3.6); squares and octagons (4.8.8) and more unusual combinations of squares, hexagons and do-decahedrons (4.6.12).

An incidental advantage of using such tessellations is that each grid pat-tern can then be identified using the unique naming scheme for tessellations before the user's own pattern and sequence are challenged. This adds another level of security to the system if desired.

22 13-07-2006 Speci(icaIionCRAYMEJ-P1344.GBA3'-2006 0712 Printed: 05-09-2006 DESC 0613835 -23 -Security Considerations 1. The system forming the invention consists of several components a. A grid of numbers known by both the user and the Authen-ticator b. If using the Craymer Grid' then, in addition to the numbers, the card orientation and the start position' must be known by both the user and the Authenticator.

c. A sequence' and pattern' which must be known ONLY by both the user and the authenticator.

2. If the grid is stolen then security is not compromised because the pattern and sequence are both required to make a successful authentication.

3. In the case of purchases, if both a credit/debit card and a grid are stolen, then the security is not compromised because the sequence and pattern are both required to make a successful authentication.

4. In the case of paper grids such as the Craymer Grid, if the pattern is known by a third party then (depending upon the required degree of security) the grid will also need to be stolen or copied. The authenticator will need to take this risk into account before he decides whether he allows third party grids to be used.

5. Depending on the desired level of security, the user could be barred from registering easily recognised patterns, e.g. straight lines. The au-thenticator could implement software rules to allow only obscure' patterns to be selected.

6. It may be thought preferable to use letters (A-Z) instead of, or as well as, numbers in order to increase the uniqueness' of the transaction code.

However, it must be considered that the more unique the number the more clues a potential eavesdropper would have to determine the pattern. For greater security the authenticator may consider that a five or six digit numeric code would be more secure than for example a four character alphanumeric code.

7. In any transaction (for example in a shop), the user should not tell the shopkeeper the transaction code and the start grid reference' and show him the grid, if he does then it may be possible (although not absolutely possible) for 23 13-07-2006 $peciuicaor1CRAYMEJ-P1344.GBA320O6 0712 Printed: 05-09-2006 DESC 0613835 -24 -the shopkeeper to determine the pattern. The more pieces of information that the user can keep private, the better.

8. For electronic transactions the software should be written such that the grid numbers, the pattern key, the grid start reference and the user's personal information are not transmitted in one data set as this would provide valuable clues as to the user's pattern. Instead, the minimal amount of data should be sent. For example the grid squares could be displayed as a graphic rather than as a set of ASCII characters.

9. All electronic transmissions should ideally be encrypted.

10. Authentication data (e.g. the transaction code) should only be transmitted for authentication with an obscure identifier that identifies the sale.

No other data should be transmitted which could give clues as to the grid num-bers or pattern.

Various specific embodiments of the method and apparatus of the inven-tion will now be described with reference to Figures 6 to 12.

Referring first to Figure 6, an on-line verification method according to the invention involves generation of a challenge grid in the user terminal, which may be an ATM or the user's computer, as described hereinafter with reference to Figure 10, or the user's portable electronic device, such as the cellular tele-phone-based system described hereinafter with reference to Figure 12.

The grid may be generated by an algorithmic or pseudo-random number-generating process. Such systems are well-known, and need not therefore be described in detail. The number generation cannot be purely random, because this would theoretically give rise to the possibility of the grid being filled with long strings of the same number, so that the verification string could then be all the same number. If any number appears in the grid more than the average number of times, it is more likely than others to be part of the user's pattern, and could therefore assist a thief in guessing the correct sequence of numbers.

While the chances of a correct guess are very small, the risk of guessing cor-rectly will be minimised by ensuring that all numbers in a 5 x 5 grid appear at least twice, but no more than three times. It may be desirable to use a grid in which all digits can appear with the same frequency. For example, a 5 x 6 grid 24 13-07-2006 SpeciIicaonCRAYMEJP1344.GBA3--2OO6 0712 Printed: 05-09-2006 DESC 0613835 -25 - has 30 cells, and therefore each digit can appear exactly three times, minimis-ing the probability of someone guessing the correct string of digits. This may be referred to as a balanced grid. In some circumstances, it may be possible to tailor the challenge grid according to the user's pattern, in order to reduce the S likelihood of the pattern being guessed. This would require the user's pattern to be made available at the user terminal or device, typically by transmission at the start of the transaction from the authenticating authority. This will generally be undesirable.

It will be understood, therefore, that references herein to "pseudo-random", "algorithm" and "algorithmically" indicate processes where the ap- pearance of randomness is created in the result, but the result is not purely ran-dom, and the process may incorporate encoding rules based, for example, on additional data. One of the factors employed in an algorithm, for example, could be a public/private data key.

The generated challenge grid is held in memory on the terminal while be-ing displayed with the challenge to the user to enter the numbers occupying the locations in the grid corresponding to the user's chosen pattern (and sequence).

The user's response is then transmitted to the authenticator along with the stored grid, for comparison with the user's pattern stored in the authentication database. If the verification set of numbers corresponds with the numbers in the transmitted challenge grid identified by reference to the user's stored pat-tern, the verification is accepted, otherwise it is rejected. It will be seen that the user's secret personal pattern is not

transmitted outside the authenticating computer. However, while the data transmitted from the user terminal to the authenticator would be encrypted, if a hacker were to intercept and decrypt this, he would have access to a clue to the user's per-sonal pattern by referring the string to the grid. The method illustrated in Figure 7 provides one way of avoiding this possible weakness. At the start of the transaction, the user terminal contacts a separate grid database which supplies to the terminal a challenge grid algorithmically selected from a large number of grids stored in the database. The challenge grid carries a unique identification code. The transaction proceeds in essentially the same way as in the method 13-07-2006 Specificabon CAAYMEJP1344.GBA3--2OO6 07 12 Printed: 05-09-2006 DESC 0613835 -26 - illustrated in Figure 6, except that the challenge grid is not transmitted to the au-thenticator; instead, the grid identification code is sent, and this is used by the authenticator to retrieve the grid from the separate grid database for the com-parison step.

In the method illustrated by Figure 8, the authenticator initially supplies to the user a large grid of numbers, the grid being substantially larger than the challenge grid used for the transaction (which is typically a 5 x 5 grid or a 7 x 7 grid). The supply of a fresh large grid may be carried out at regular intervals, perhaps automatically, to the terminal, and the grid used is stored in a grid da- tabase by the authenticator for reference. At the start of the transaction, the au-thenticator specifies to the user a pseudo-randomly generated grid reference which serves as a starting point for the terminal to extract from the larger grid the challenge grid. For example, a 5 x 5 grid may be extracted using the grid reference as the top left-hand corner. The user terminal then needs only to transmit to the authenticator the numerals entered by the user in response to the challenge for the verification comparison to be carried out by the authentica-tor.

It will be understood that, while each of these methods is described with reference only to the transmission of the numerals entered by the user, with other grid identifiers where necessary, these will necessarily be accompanied by some account number or other personal identifier to be verified.

In an adaptation of the method illustrated in Figure 8, the user terminal selects the grid reference start point pseudo-randomly itself at the start of the transaction, and this is transmitted along with the user's challenge numerals to the authenticator, who can then find the challenge grid from the stored grid for the user terminal.

In another adaptation of this method, the user terminal employs a simple algorithm to generate from the large grid of, say, 1000 numbers a challenge grid of, say, 25 numbers which are not a discrete contiguous sub-set of the larger grid. This method has the advantage that the algorithm does not need to be to- tally secure. For example, the user could be sent a virtual larger grid of num-bers once a month by the authenticator. Since the authenticator knows both the 26 13-07-2006 SpecificaonCRAYMEJ-'P1344.GBA32OO6 0712 Printed: 05-09-2006 DESC 0613835 -27 - algorithm and the virtual grid, it can work out what numbers to expect. It, how-ever, the algorithm becomes known, the hacker would not have access to the virtual grid, which would be different for each person and would be changed regularly. So while at worst the hacker might know the grid positions in the vir-tual grid which would be used to generate the challenge grid, he will not know the numbers occupying the particular virtual grid, and can therefore not gener-ate the challenge grid.

In a further adaptation, instead of one large grid, the user terminal is sup-plied with a plurality of challenge grids by the authenticator in the same manner as for the large grid, each grid carrying an identifier. The authenticator could then indicate to the user terminal at the start of the transaction the grid to be used, by transmitting the relevant identifier, or the user terminal could algo-rithmically select one of the grids and send its identifier along with the numerals entered as a result of the challenge.

Figure 9 illustrates yet another approach. The local terminal is arranged to run an algorithm at the start of the transaction which uses the date and time of day and a terminal and/or personal identifier to generate a pseudo-random string of numbers. Such algorithms are wellknown for use with securing per- sonal computers or personal digital assistants (PDAs), the user having a hand- held electronic key device which displays a key number which changes at regu-lar intervals. The device to be secured runs the same algorithm using the same starting data to generate the same numbers internally in synchrony with the key device. The user enters the key number to unlock the computer or PDA. In the present embodiment, that type of algorithm will be extended to generate, say, a 25 digit key number instead of the 5 or 6-digit number conventionally used and to fill the challenge grid with these numbers. The algorithm can use key data such as a terminal identifier, a personal identifier, and account number, a mo-bile telephone number, where the terminal is a mobile telephone, or combina-lions of these. The authenticator uses the same algorithm to generate the same 25-digit string based on the same key data and the transaction time stamp. In this way, the verification can be carried out without the need for any grid information to be transmitted. As an alternative to the use of the time 27 13-07-2006 SpeciIicaoriCRAYMEJP1344.GBA3-2OO6 07 12 Printed: 05-09-2006 DESC 0613835 -28 -stamp, the algorithm may calculate the grid based on the preceding time as well as the current time and use both (or indeed several, depending on the time lati- tude allowed by the system) to determine whether any of them produces a pat-tern match to verify identity.

It will be understood that hybrid methods between this method and the other methods described could be used. For example, the number-generation algorithm could be used to generate a code identifying a grid to be selected from a separate database, or from a plurality of grids pre-stored in the terminal, the authenticator then running the algorithm with the same "seeds" to generate the code and thereby identify the correct grid for comparison purposes.

Figure 1 0 illustrates typical apparatus used in an on-line transaction. A user terminal, which could be, for example, an ATM, or even a personal com-puter, has a central processing unit 100 connected to a display screen 101, a numeric key pad 102 and a card reader 103. A network connection 104, for ex- ample via the Internet represented at 105, leads to a remote transaction authen-tication processor 106, linked to a database 107 which stores user details and the associated personal identification pattern (PIP). To start the transaction, the user inserts a personal card 108, for example a debit or credit card, into the reader 103. The user's account number is read from the card, and the terminal then generates a challenge grid 109, for example of 25 squares containing pseudo-randomly-generated digits from 0 to 9, and displays it on the display screen 101 with an invitation to the user to enter on the key pad 102 the digits occupying the user's PIP in the grid. The terminal then initiates a connection to the transaction authentication processor 106 to transmit in encrypted form the user's account number, the amount of the transaction, the digits entered by the user, and the challenge grid. On receipt of these data, the authentication proc-essor 106 uses the account number to retrieve from the database 107 the user's PIP and credit/account data. The verification is then carried out as de-scribed hereinbefore with reference to Figure 6, and if identity is confirmed and the transaction is otherwise acceptable, the authentication processor 106 transmits back to the terminal an authorisation code so that the terminal can complete the transaction.

28 13-07-2006 SpeciIicaon CRAYMEJP1344.GBA3-2OO6 07 12 Printed: 05-09-2006 DESC 0613835 -29 -Figure 11 illustrates apparatus performing a variant of this procedure, as described with reference to Figure 7. This adds a separate challenge grid proc-essor 110 having a database 111 of challenge grids, each having a unique identifier associated with it. The grid processor 110 may be remote both from the user terminal and from the authentication processor 106, and the connec-tion between them may via a network link 112, for example via the Internet 105.

Figure 12 illustrates another embodiment, in which the user's mobile or cellular telephone 120 serves as the user terminal. In this case, the telephone also stores the user's personal and account details, instead of these being stored in a separate transaction card. The process can be as described with reference to any of Figures 6 to 9, with transmissions to and from the authenti-cation processor being carried wirelessly, for example using any of the wireless data networks or methods, such as GPRS.

Figure 13 is a flow chart of yet another method, which is a development of the method illustrated in Figure 9. After the grid is generated by the algorithm and the user enters a response string, another algorithm is used to generate from the response string and one or more of the identifiers mentioned in the method described with reference to Figure 9 a "token", for example in the form of a ten-digit number (or perhaps a string of letters and numbers) which dis- guises the response, but in a manner which will be recognisable to the authenti- cating authority having the same identifiers available. The token is then trans-mitted to the authenticating authority together with at least one of the identifiers.

The authenticating authority stores the token temporarily while using the same algorithm and the identifier(s) to calculate the same 25 digit string to rec-reate the challenge grid. The user's secret pattern is retrieved from the pattern database and is used to extract from the challenge grid the expected correct response. In a final step, this expected response (a string of 4 numbers, say) is entered into the token algorithm using the necessary identifiers, at least one of which was transmitted with the token from the user, to calculate the token. This can then be compared with the transmitted token. If they are the same, identity is verified, otherwise the transaction is rejected.

29 13-07-2006 SpeciIicaonCRAYMEJ-P1344.GBA3--20O6 0712 Printed: 05-09-2006 DESC 0613835 -30 - A variation of this process may be used to secure the transmission of e-mail messages. The sender runs on his e-mail terminal a verification process which could, for example, be based on identifiers stored in his terminal (a per- sonal computer or a portable communications device, for example). This gen-erates a challenge grid using a number generating algorithm as described with reference to Figures 9 and 13. The response is then converted into a token, as described with reference to Figure 13, the token also encoding the transmission date and time. The token is inserted into the e-mail message and transmitted to the recipient. The recipient then runs a corresponding verification process which uses the attached key to confirm the identity of the sender, according to pre-stored information. The date and time of transmission as indicated on the e-mail message are used by the verification process to regenerate the token, which is carried out in the manner described with reference to Figure 13, and if the tokens do not match, then this is an indication that the e-mail has been tam-pered with or was not sent by the supposed sender.

13-07-2006 SpeciIicaonCRAYMEJP1344.GBA3-2OO6 0712

Claims

Printed: 05-09-2006 CLMS 0613835 -31 -

CLAIMS

1. A method for verifying a person's identity, comprising a registra-tion step of storing for the person a personal pattern of a number of locations on a grid in association with personal identification data, and subsequently using the pattern in a verification process, wherein the subsequent verification proc-ess comprises the steps of: (a) presenting to the person a challenge grid of locations occupied by a pseudo-random set of symbols, and challenging the person to identify a re-sponse set of symbols occupying locations in the challenge grid corresponding to the stored personal pattern; (b) receiving from the person the response set; (C) generating from the challenge grid and the stored pattern a verifica-tion set of symbols occupying locations in the challenge grid corresponding to the stored personal pattern; (d) comparing the response set of symbols with the verification set of symbols; and (e) verifying the identity of the person if the response set is the same as the verification set.

2. A method according to Claim 1, wherein the registration step corn-prises first providing the person with a grid and inviting the person to select the personal pattern of locations.

3. A method according to Claim 1 or 2, comprising communicating the identified symbols to a transaction authorising computer at a location remote from the person and conducting steps (b) to (e) in said authorising computer.

4. A method according to Claim 3, wherein step (a) comprises gen-erating the challenge grid in a user terminal and transmitting to the authorising computer the verification set of symbols and the challenge grid or data enabling the authorising computer to identify or recreate the challenge grid.

5. A method according to Claim 4, comprising using an algorithm in the user terminal to generate a pseudo-random string of symbols according to the date and/or time of day and identity data for the terminal and/or the person to construct the challenge grid, and transmitting to the authorising computer at 13-07-2006 SpeciIicatioriCRAYMEJP1344.GBA3-2006 0712 Printed: 05-09-2006 CLMS 0613835 -32 -least the verification set of symbols and identity data, the authorising computer using the same algorithm and said identity data and the date and/or time of day to generate the same pseudo-random string of symbols, thereby to recreate the challenge grid.

6. A method according to Claim 5, comprising using a second algo-rithm to generate from the verification set and at least one factor from: (i) the transaction time and/or date; (ii) a personal or account identifier; (iii) a terminal identifier; and (iv) a public/private data key; a token consisting of a string of symbols concealing the verification set, and wherein the step (C) comprises using the recreated challenge grid to gener-ate the verification set, applying the second algorithm using the factor or factors to generate a token from the verification set, and step (d) comprises comparing the received token with the generated token.

7. A method according to Claim 3, wherein step (a) comprises algo-rithmically selecting in a user terminal one of a plurality of challenge grids previ-ously supplied to said user terminal by a transaction authorising body or the transaction authorising computer and stored in the terminal, and transmitting to the transaction authorising computer the verification set of symbols and data identifying to the authorising computer the algorithmically selected grid.

8. A method according to Claim 3, wherein step (a) comprises algo-rithmically selecting in a user terminal a start reference point in a large matrix of symbols previously supplied to said user terminal by a transaction authorising body or the transaction authorising computer and stored in the terminal, pre-senting a challenge grid derived from the large matrix using the start reference point, and then transmitting to the authorising computer the verification set of symbols and the start reference point.

9. A method according to Claim 3, wherein step (a) comprises algo-rithmically selecting in a user terminal a predetermined number of symbols from a large matrix of symbols previously supplied to said user terminal by a transac-tion authorising body or the transaction authorising computer and stored in the 2 13-07-2006 SpeciIicaoriCRAYMEJ-P1344.GBA3 2006 0712 Printed: 05-09-2006 CLMS 0613835 -33 - terminal, presenting a challenge grid of said selected symbols, and then trans-mitting to the authorising computer the verification set of symbols, and wherein in step (c) the authorising computer applies the same algorithm to select from the large matrix previously supplied the same symbols to reconstruct the chal-lenge grid.

10. A method according to Claim 3, wherein step (a) comprises re-ceiving in a user terminal a start reference point transmitted thereto by the authorising computer, the start reference point indicating a position in a large matrix of symbols previously supplied to said user terminal by an authorising body or the authorising computer and stored in the terminal, presenting a challenge grid derived from the large matrix using the start reference point, and then transmitting to the authorising computer the verification set of symbols.

11. A method according to Claim 3, wherein step (a) comprises re-trieving from a database of grids independent of the authorising computer an algorithmically selected one of a plurality of grids stored in said database, said grid having a unique identifier, and transmitting to the authorising computer the verification set of symbols and said grid identifier, and step (c) comprises the authorising computer transmitting the identifier to the independent database to retrieve the challenge grid.

12. A method according to any of Claims 4 to 11, wherein the user terminal is an automated teller machine (ATM).

13. A method according to any of Claims 4 to 11, wherein the user terminal is a computer connectible to the authorising computer via a network connection.

14. A method according to any of Claims 4 to 11, wherein the user terminal is a portable electronic device connectible to the authorising computer through a wireless connection.

15. A method according to any of Claims 4 to 11, wherein the trans-mission to the authorising computer includes verbal communication.

16. A method according to any preceding claim, wherein the person also communicates to the authorising computer information from an identity or transaction memory device.

3 13-07-2006 Specificaan CRAYMEJP1344.GBA32OO6-O7 12 Printed: 05-09-2006 CLMS 0613835 -34 - 17. A method according to Claim 16, wherein the memory device is in or on a credit or debit card.

18. A method according to Claim 16, wherein the memory device is embedded within a portable electronic device carried by the person.

19. A method according to any preceding claim, wherein personal pat-tern includes a sequence in which the locations are used.

20. A method according to Claim 1, 2 or 3, wherein the challenge grid is presented as a pre-printed sheet with a plurality of symbols in respective grid positions.

21. A method according to Claim 1, 2 or 3, wherein in step (a), the challenge grid is provided to the person from a memory chip in a credit or debit card.

22. A method according to Claim 21, wherein in step (a), the grid is read from said memory chip by a card-reader.

23. A method according to Claim 22, wherein said card reader is pro-vided in a portable electronic device in the possession of the person.

24. A method according to Claim 1 or 2, comprising communicating the identified symbols to an electronic device on or in a transaction or identifica-tion card carried by the person.

25. A method according to Claim 1 or 2, comprising communicating the identified symbols to an access control computer.

26. Apparatus for use in verifying a person's identity, comprising means for receiving and storing identification data for the person and a linked pattern of locations on a grid, electronic means at the person's location for pre-senting to the person a challenge grid and an invitation to the person to identify in response thereto symbols occupying locations in the challenge grid corre-sponding to the stored personal pattern, and verification means for receiving from the person the response set, the verification means being arranged to gen-erate from the challenge grid and the stored pattern a verification set of symbols occupying locations in the challenge grid corresponding to the stored personal pattern, to compare the response set of symbols with the verification set of sym- 4 13-07-2006 SpeciIicationCRAYMEJ-P1344GBA3-- 2OO6 07 12 Printed:

05-09-2006 CLMS 0613835 -35 -bols, and to verify the identity of the person if the response set is the same as the verification set.

27. Apparatus according to Claim 26, wherein the linked pattern of lo-cations is a pattern chosen initially by the user.

28. Apparatus according to Claim 26 or 27, wherein the verification means comprises a transaction authorising computer.

29. Apparatus according to Claim 26 or 27, wherein the electronic means is a user terminal remote from the transaction authorising computer.

30. Apparatus according to Claim 29, wherein the user terminal is pro-grammed to generate the challenge grid, and arranged to transmit to the transaction authorising computer at a location remote from said user terminal the verification set of symbols and the challenge grid or data enabling the transaction authorising computer to identify or recreate the challenge grid.

31. Apparatus according to Claim 29, wherein the user terminal is pro-grammed to use an algorithm to generate a pseudo-random string of symbols according to the date and/or time of day and identity data for the terminal and/or the person to construct the challenge grid, and arranged to transmit to the transaction authorising computer at least the identity data, and wherein the transaction authorising computer is programmed to use said identity data and the date/time of day to generate, using the same algorithm, the same pseudo-random string of symbols, thereby to recreate the challenge grid.

32. Apparatus according to Claim 31, wherein the user terminal is pro-grammed to use a second algorithm to generate from the verification set and at least one factor from: (i) the transaction time and/or date; (ii) a personal or account identifier; (iii) a terminal identifier; and (iv) a public/private data key; a token consisting of a string of symbols concealing the verification set, and the transaction authorising computer is programmed to use the recreated challenge grid to generate the verification set of symbols, to apply the second algorithm using the factor or factors to generate a token from the verification 13-07-2006 Specificaor1CRAYMEJ-P1344.GBA3-2OO6 0712 Printed: 05-09-2006 CLMS 0613835 -36 - set, and then comparing the received token with the generated token to estab-lish or deny verification.

33. Apparatus according to Claim 29, wherein the user terminal is pro-grammed to select algorithmically one of a plurality of challenge grids previously supplied to said user terminal and stored therein, and arranged to transmit to the authorising computer the verification set of symbols and data identifying the selected grid.

34. Apparatus according to Claim 29, wherein the user terminal is pro-grammed to select algorithmically a start reference point in a large matrix of symbols previously supplied to said user terminal and stored therein, to present a challenge grid derived from the large matrix using the start reference point, and then to transmit to the authorising computer the identified symbols and the start reference point.

35. Apparatus according to Claim 29, wherein the user terminal is pro-grammed to select algorithmically a predetermined number of symbols from a large matrix of symbols previously supplied to said user terminal by a transac-tion authorising body or the transaction authorising computer and stored in the terminal, to present a challenge grid of said selected symbols, and then to transmit to the authorising computer the verification set of symbols, and wherein the authorising computer is programmed to apply the same algorithm to select from the large matrix previously supplied the same symbols to reconstruct the challenge grid.

36. Apparatus according to Claim 29, wherein the user terminal is pro-grammed to receive a start reference point transmitted thereto by the verification computer, the start reference point indicating a position in a large matrix of symbols previously supplied to said user terminal and stored therein, to present a challenge grid derived from the large matrix using the start refer- ence point, and then to transmit to the transaction authorising computer at a lo-cation remote from the user terminal the identified symbols.

37. Apparatus according to Claim 29, wherein the user terminal is pro-grammed to retrieve from a database of grids independent of the transaction authorising computer and of the person an algorithmically selected one of a plu- 6 13-07-2006 SpeciIicaon CRAYMEJF'l 344.GBA3 -2006 07-12 Printed: 05-09-2006 CLMS 0613835 -37 -rality of grids stored in said database, said grid having a unique identifier, and to transmit to the transaction authorising computer at a location remote from the user terminal the identified symbols and said grid identifier, and wherein the transaction authorising computer is programmed to transmit the identifier to the independent database to retrieve the challenge grid.

38. Apparatus according to any of Claims 29 to 37, wherein the user terminal is an automated teller machine (ATM).

39. Apparatus according to any of Claims 29 to 37, wherein the user terminal is a computer connectible to the transaction authorising computer via a network connection.

40. Apparatus according to any of Claims 29 to 37, wherein the user terminal is a portable electronic device connectible to the transaction authoris-ing computer through a wireless connection.

41. Apparatus according to any of Claims 26 to 40, wherein the elec-tronic means is arranged to communicate to the transaction authorising com-puter information from an identity or transaction memory device.

42. Apparatus according to Claim 41, wherein the memory device is in or on a credit or debit card.

43. Apparatus according to Claim 41, wherein the memory device is embedded within a portable electronic device which can be carried by the person.

44. Apparatus according to Claim 42, wherein the electronic means comprises, in combination, a memory chip in a card, and a card reader.

45. Apparatus according to Claim 44, wherein the card reader is in-corporated into a mobile or cellular telephone.

46. Apparatus according to Claim 26 or 27, wherein the verification means is an electronic device in or on a transaction or identification card which can be carried by the person.

47. An access control system, comprising apparatus according to Claim 26 or 27, wherein the verification means is an access control computer programmed to allow access in response to verification of identity.

7 13-07-2006 SpeciIicaonCRAYMEJP1344.GBA3-2OO6 0712 Printed: 05-09-2006 CLMS 0613835 -38 - 48. An access control system according to Claim 47, wherein the ac-cess control computer controls release of a lock or latch.

8 13-07-2006 SpeciIicaonCRAYMEJP1344.GBA32OO6 0712