GB2164186A - Signature verification - Google Patents

Abstract

In order to permit verification of a signature at a point remote from initial registration of a standard signature and without reference to a central data bank, the process of generation of the standard signature at the point of registration is analysed and a transform of the standard signature derived therefrom. Both the signature and the transform are recorded on an item, for example a traveller's cheque or a credit card. When the traveller's cheque is presented for encashment, the signature of the person presenting it may be verified by deriving a transform of the signature as generated by the person and comparing the transforms. Whereas the signatures may appear visually identical, a fraudulent signature will not have been produced in the same manner as the original standard signature and the transforms will differ.

Description

SPECIFICATION Signature verification This invention relates to signature verification, and in-particularto methods of use therein.

According to the present invention there is provided a methodfor use in verifying a signature at a point remote from a point of initial registration of the signature and without reference to a central data bank.

including the steps of analysing the process of generation of the signature atthe point of initial registration, deriving a transform therefrom and recording the transform and the signature on an item, whereby at the remote pointthe signatu re of the person presenting the item can be verified by analysing the process of generation ofthe signature by said person byte same method as employed at said point of registration, wherebyto produce a corresponding transform ofthe signature, and by comparing the transform ofthesignature on said item and the transform derived atthe remote point.

According to another aspect ofthe present invention there is provided a method for use in verifying a signature at a point remote from a point of initial registration of the signature and without reference to a central data bank, wherein the process of generation ofthe signature was analysed atthe point of initial registration and a transform derived therefrom was recorded on an item, the method comprising, at the remote point, analysing the process of generation of the signature by said person using the same method as employed at said point registration, producing a corresponding transform ofthe signature, and comparing the transform ofthe signature on said item as presented bythe person and the transform derived at the remote point.

According to a further aspectofthe present invention the items such as a bank cheque, traveller's cheque, credit card orsecuritycard has recorded thereon or is suitableforhaving recorded thereon both the person's signature and the transform ofthe signature.

There are various situations in which the verity of a signature needs to be established at a distance from its original point of generation,for example, during the counter-signature oftravellers cheques upon encashment orwhen credit or similar cards are employed in a substantial transaction.

The present invention proposes a method of establishing the verity of a signature at a distance from its original point of generation and without reference to a central data bank. The method is applicable to all situations where identity has to be established and when P.l.N. or similartechniques are inadequate or impractical, and provides a ready means of establishing the legitimate ownership of a credit or similar card. The method does not pre-suppose actions on the part ofthe signatory otherthan those currently accepted during transactions involving the purchase of goods, services or money, or the profering of a signature for security/entry, and it does not preclude the presently accepted methods employed by the banking and travellers cheques industriesforthe verification of signatures bya human agent.

For the purposes ofthevalidation method ofthe present invention it is necessaryto analyse the processes of generation of a signature in order to extract from it certain key aspects, descriptive of the signature. These aspects are then included as an entry additional to the signature itself in the signature space on the credit card, travellers cheque or other item bearing the signature.

The analysis ofthe signature maytakevarious forms. For example, an analysis ofthe rate of change of velocities, directions, amplitudes, etc. within unit time periods during signature generation, as proposed in our co-pending Application No.8133884 (Serial No.21 09970A) (A. E. Brewster-D. P. Newstead A. J. Hicks 84-5-2). Alternatively, optical scanning processes which likewise lend themselves to the production of a coded surrogate ofthe signature which is capable of expression in a simple form, hereinafter referred to as a transform ofthe signature, may be employed. Such an optical method is disclosed in ourco-pending Application No.8422286 (Serial No. ) (D. P. Newstead-R. E. Cooke 9-7).

By way of illustration atypical use of the verification process will now be described. Upon purchase of travellers cheques it is currently necessaryforthe client to sign each cheque individually before he leaves the counter and in the presence ofthe issuer.

When a travellers cheque is subsequently enchashed the client must sign it again and a simple human comparison is made between the two signature by the bank clerk, shop assistant etc. concerned.

What is now proposed isthatthe client, upon purchasing travellers cheques,would be asked to supply a number, for example three, of specimen signatures by means of a sensing device including means of providing a transform ofthe signature, for example involving use ofthe method of Application No 8133884to provide an identification code, or optical equipment capable of providing a transform of the signature itself as in Application No.8422286 (D. P.

Newstead-R. E. Cooke 9-7).

The issuing station forthetravellers cheques would then reproduce the client's signature upon each ofthe purchased cheques. This may bewithin the space provided within the presenttravellers cheques format As well as the signature, h owever,the derived transform would be reproduced on the cheque. The transform may, for example, appear as a coded underlining or borderto the signature. The transform values may appear in a variety offorms amd might typically assumethe form of a series of bytes descriptive of the transform. For example the bits within the byte may be represented as dots for '0's and dashes for '1's. These seriallyform the elements of an underline and might reasonably completethefourth or bottom line of a rectangle indicating the space for signature. These arrangements would be part ofthe device for reproducing the clients signature on a cheque, referred to earlier. In a possible embodiment the machine would also printthethreesidesofan endorsing box in some pattern superficially resemb ing the transform with the transform itself as the remaining side.

Upon subsequent presentation ofthetravellers chequeforencashmentorpurchaseofgoods or services, theclient may counters;gn the cheques as normal in the presence of a bank clerk or shop assistant etc. lfthe value ofthe cheque is small a simple human comparison ofthesignaturesthem- selves maysuffice, howeveratleastforlarge cheque values countersignature generation atthe point of encashmentwould involve use of a similar deviceto that used atthe point of issue ofthe cheque in order to obtain a transform ofthe signature by an identical method atthe point of encashment.Machine comparison ofthetwotransforms would then be performed as well as visual comparison ofthesignaturesthem- selves. During the machine comparison, the trans- form would be examined for its content; as would the transform ofthe locally generated signature derived by an identical equipment. These two elementswould provide the data for comparison < Variations in a genuine signature areto be expected and the comparison algorithm would be conceived accordingly. The object of the exercise being to establish to a given and acceptable level of statistical probability that the local signature was genuine. The actual method ofcom- parison is therefore amenable to a number of conventional techniques.Whereas perfect forgeries of a signature are difficultto detect by pattern recognition processes,forgeries do, however, as can be shown in the case of the methods employed in Application No.

8133884, give rise to widely differing transforms due to changes in the method of generation of the signature bytheforger in comparison with thetrue signatory.

The method of reproducing the client's signature on each ofthe purchased travellers cheques atthe point of issue involved in the verification procedure ofthe present invention offers a convenience to a client purchasing a large number of travellers cheques, since it relieves him ofthe burden ofsigning each individual cheque and ensures thatthe cheques are properly signed before the client leaves the counter, following the required practice of most issuers.

The procedure described above will be of benefitto security applications and particularly to those whose business involves moneytransactions, rendering the wholesaletheftofblankcheques and subsequent fraudulent use, or the theft ofvalidly issued cheques and their subsequentfraudulent encashment,con- siderably more hazardous than at present. The procedure isalsoapplicableto use with conventional bank cheques.

To combat possible countermeasures by persons seeking to defraud the operator ofthe signature verification system, for example a travellers cheque organisation, the method by which the transform is derived may be controlled by a security keydissemi natedthroughtheoperator's networkattimes deemed appropriate. This involves the application of encryption techniques to the transformed values prior to their being printed as an accompanimentto the conventional signature.

Claims (9)

1. A method for use in verifying a signature ata point remote from a pointof initial registeration of the signature and without reference to a central data bank, includingthe steps of analysing the process of generation ofthe signature at the point of initial registration, deriving a transform therefrom and recording the transform and the signature on an item, wherebyatthe remote pointthe signature ofthe person presenting the item can be verified byanalys- ing the process of generation ofthe signature bysaid person bythesame method employed at said point of registration, whereby to produce a corresponding transform of the signature, and by comparing the transform ofthe signature on said item and the transform derived atthe remote point.

2. A method for use in verifying a signature at a point remote from a point of initial registration ofthe signature and without reference to a central data bank, wherein the process of generation ofthe signature was analysed atthe pointof initial registration and a transform derived therefrom was recorded on an item, the method comprising, atthe remote point, analysing the process of generation ofthe signature by said person using the same method as employed at said point of registration, producing a corresponding transform ofthe signature, and comparing the trans- form ofthe signature on said item as presented bythe person andthetransform derived atthe remote point.

3. A method as claimed in claim 1 or claim 2, wherein thetransforms are compared visually.

4. A method as claimed in claim 1 or claim 2, whereinthetransformsarecompared by a machine.

5. A method as claimed in any one ofthe preceding claims, wherein a transform is derived electricallyin responsetovariationsintherateof change ofvelocities, directions oramplitudeswithin unittime periods during generation ofthe signature.

6. A method as claimed in any one of claims 1 to 4, wherein a transform is derived by an optical scanning process.

7. A method as claimed in any one of the preceding claims, wherein the item comprises a bank cheque. a travellers cheque, a credit card or a security card.

8. An item such as a bank cheque, a travellers cheque, a credit card or a security card, for use in the method of any of claims 1 to 7, having recorded thereon or suitable for having recorded thereon both the person's signature and the transform.

9. A method for use in verifying a signature as claimed in any preceding claim and substantially as herein described.