GB2243934A - Access control - Google Patents

Abstract

A card reading device 12 reads a unique identity code from a card 24 presented by an authorised user 26. The code identifies a particular set of two physical characteristics reference values stored in a memory 14 which are then supplied to a comparator 16. The reference values are compared with actual values measured by sensors 18, 20 at the access point. The characteristics measured may be, for example, fingerprint and voice data. If the actual values are substantially comparable to the reference values, within predetermined parameters the comparator 16 issues an acceptance code opening locking means 22 to permit access to the protected area. <IMAGE>

Description

METHOD AND APPARATUS FOR ACCESS CONTROL This invention relates to a method and apparatus for access control so as to permit or deny access to a secured area.

Access control systems are commonly provided where access to a predetermined location or area is to be restricted to authorised personnel only. Such a situation would be commonly encountered within defence establishments or areas utilising or containing sensitive information. In such cases it is extremely important to control those persons who have access to these area and to ensure that non-authorised personnel are not permitted access.

Several methods have been proposed in the past in order to accomplish such a requirement, for example, the issuance of coded cards or key devices to unlock or open access points to the designated area. A problem with such an arrangement is that the physical nature of these devices permits their duplication or theft and hence use by unauthorised personnel. It is not of course possible for a key or a coded card to determine the identity of the person who is using the card to gain access to the area.

In an effort to overcome these limitations it has become common to link such card or key systems with a sensor provided at the point of access which is operative to sense or measure some particular physical characteristic of the card user. Details of that physical characteristic, for example, voice or fingerprint or retina pattern etc. of authorised personnel are stored centrally and an identity code for the authorised card holder is encoded onto the card.

When the card is placed in a card reader the physical characteristic stored in the system is compared with the same physical characteristic of the person currently using the card. If the stored and the actual characteristic are substantially identical then access will be permitted.

Of course, whilst such arrangements permit increased security compared to card or key systems alone there are limitations to the use of these so called "biometric" sensors. Firstly it is possible to provide apparatus or means which can mimic or fake the required physical characteristic and so permit unauthorised access in conjunction with a valid card or key. In view of the security requirements for these areas such defects in access control are a considerable disadvantage.

Secondly the comparison of the stored and the measured physical characteristic value has to be made with a high degree of accuracy in order to be reasonably certain of the identity of the system's user. This requirement causes problems in that a large amount of storage capacity is necessary to hold a stored value which is sufficiently accurate for comparison purposes.

Further this degree of accuracy itself can cause problems as any physical characteristic will tend to vary from time to time for any one person. Thus there will be a greater chance of preventing access to an authorised person if the variation in the physical characteristic is limited.

It is an object of the present invention therefore to provide a method of controlling access to a defined location or area with a greater degree of security than hithertofore possible.

It is a further object of the invention to provide apparatus for the control of access to the predefined location or area.

With the first object in view the invention provides a method of access control comprising the steps of measuring reference values for two physical characteristics for an authorised person, storing the said reference values in a memory, inputting an identity code at an access point, comparing actual physical characteristics as measured at the access point by sensor means with the stored reference values and permitting access only if both measured characteristics match both stored characteristics within defined parameters.

The identity code may be imputted by way of a numeric key pad or could be stored on or in a key card or electronic key. A combination of these methods may be used for additional security.

The memory in which the reference values for the two physical characteristics are stored may be in a comparator contained within the card reader or may be stored in or on the key card itself and read by the card reader for the comparison. Alternatively the memory may be located in a central computer some distance from the access point.

The predetermined address code may be stored in or on the key card itself in which instance the code is automatically read and inputted by the card reader to identify an authorised user. Alternatively the address code may be a numerical sequence issued to the authorised user which is input using a key pad provided at the access point.

When the reference values are stored in a comparator the identity code is preferably operative to identify the particular set of reference values stored for the card's authorised user and recall same for comparison with the measured values.

Preferably the two physical characteristics for the authorised person for which reference values are measured are voice and fingerprint data.

The method proposed overcomes known disadvantages in that the reference values for the physical characteristics do not need to be stored with the same precision that would be required for an accurate comparison of a single characteristic. Thus less storage capacity is required for a single reference value than would be required for a single sensor system.

This lack of precision also permits slight variations in one or other of the characteristics, as might normally be expected to occur, whilst still giving an accurate identification of the card user by verification of the second characteristic.

With the second object in view the invention also provides an access control system including, at an access point, two sensors operative to measure two different physical characteristics of the system's user, identity code input means operative to receive an identity code from the system's user and associated with a comparator operative to compare the measured characteristics with reference values stored in a memory and identified by the identity code, the system further including means to permit access only if the comparison result is within predefined parameters.

Advantageously the system includes a key card or an electronic key and a reader operative to read the identity code which is encoded onto the card or key.

Preferably the key card contains a predetermed identity or address code which is read by the card reader and is operative to identify in a memory store the particular physical characteristics which relate to the card's user.

Advantageously one sensor is operative to determine the card user's voice pattern and a second sensor is operative to determine the card user's fingerprint pattern.

In a preferable embodiment of the invention the key card is electronically encoded with the reference values for the two physical characteristics, which reference values are read by the card reader and supplied to the comparator for comparison with the measured values.

The invention will be described further by way of example with reference to the accompanying drawing in which the single figure is a simplified block diagram showing a preferred embodiment of the invention.

Referring to the single figure, apparatus for access control according to an aspect of the invention includes a card reading device 12 operative to accept a pre-programmed key card and read information encoded thereon. The card reader 12 is connected to a memory store 14 which contains within it a number of sets of two predetermined physical characteristic values. Each set of values refers to one specified authorised person and each set is identified by a unique identity code which is to be encoded on that person's key card.

The system also includes two sensors 18, 20 positioned and operative so as to measure and record physical characteristic data of a card user.

Preferably a first sensor 18 is operative to record voice pattern information and a second sensor 20 is operative to record and measure fingerprint pattern data. The recorded data from voice sensor 18 and fingerprint sensor 20 is supplied to a comparator 16 which is also connected to the memory store 14. Thus the data measured and recorded by sensors 18, 20 can be compared with stored reference data. The results of this comparison produce an output which, if the comparison is acceptable within predetermined perameters, will result in locking means 22 being opened to permit access to the secured area.

The system additionally includes a pre-programmed key card 24 which contains encoded thereon, by for example, a magnetic strip or bar code or other means, an address code which is operative to identify that set of reference values relating to the card's authorised user. These reference values, which in the exemplified embodiment is voice and fingerprint data, are pre-recorded and stored in a memory store 14 as previously described.

The method of using the system according to this aspect of the invention is as follows.

A key card 24 is presented by its authorised user 26 to the card reader 12 which reads from the card, the user's unique identity code. This identity code is supplied to the memory store 14 which recalls the set of physical characteristic data relating to the card's user 26. This information is supplied to the comparator 16.

Simultaneously the voice sensor 18 and the fingerprint sensor 20 are activated and measure the corresponding physical characteristics of the user 26.

For example, the user 26 will be asked to place his finger on a screen which will have a sensor array operative to measure and record the fingerprint pattern.

Additionally the user will be asked to repeat a specific phrase or word and the voice pattern for this phrase or word will also be recorded. These details are supplied by the sensors 18, 20 to the comparator 16 where they are compared with the pre-recorded data recalled from the memory store 14. If the results of the comparison are acceptable within predetermined parameters the comparator 16 will issue an acceptance code operating the locking means 22 and permitting the user 26 access to the secured area. If the results of the comparison are not acceptable then either a repeat physical characteristic test will be required and/or the system will automatically sound an alarm.

In an alternative embodiment the key card 24 also stores the necessary reference values for the physical characteristics which information is therefore read by the card reader simultaneously with the key card's insertion therein. Thus the memory store 14 can be omitted as the reference values are supplied direct from the card reader 12 to the comparator 16 for comparison with the equivalent data obtained by sensors 18, 20.

It will be appreciated that the invention is not confined to the foregoing examples and variations may be made thereto within the scope of the invention. For example, although the exemplified embodiment makes use of voice recognition and fingerprint data any combination of known sensor technology could be used, for example, voice, fingerprint, retina pattern etc.

Additionally, the key card 24 need not contain a unique identity code, rather a key pad could be placed near the card reader requiring the input of a specified numerical code which is issued to the card user 26. Other variations are also possible.

Claims (14)

1. A method of access control comprising the steps of measuring reference values for two physical characteristics for an authorised person, storing the said reference values in a memory, inputting an identity code at an access point, comparing actual physical characteristics as measured at the access point by sensor means with the stored reference values and permitting access only if both measured characteristics match both stored characteristics within defined parameters.

2. A method as claimed in claim 1 in which the identity code is inputted by way of a numeric key pad.

3. A method as claimed in claim 1 which includes the step of recording the identity code on a recording media and presenting same to inputting means at an access point.

4. A method as claimed in claim 3 in which the memory for storing the two physical characteristic reference values is located in or on the recording media and the method includes the step of reading the reference values off the media at the access point.

5. A method as claimed in any prededing claim in which the memory is located in a central computer some distance from the access point and the method includes the steps of encoding actual physical characteristics measured at the access point and transferring same to the central computer for comparison.

6. A method as claimed in any of claims 1, 2 or 5 in which the reference values are stored in a comparator and the identity code is used to identify the particular set of reference values stored for the card's authorised user and recall same for comparison with the measured values.

7. A method as claimed in any preceding claim in which the two physical characteristics for the authorised person for which reference values are measured are voice and fingerprint data.

8. An access control system including, at an access point, two sensors operative to measure two different physical characteristics of the system's user, identity code input means operative to receive an identity coder from the system's user and associated with a comparator operative to compare the measured characteristics with reference values stored in a memory and identified by the identity code, the system further including means to permit access only if the comparison result is within predefined parameters.

9. A system as claimed in claim 8 which includes an electronic key card and a card reader operative to read the identity code which is encoded onto the key card.

10. A system as claimed in claim 9 in which the key card contains a predetermined identity code which is read by the card reader and is operative to identify in a memory store the particular physical characteristics which relate to the card's user.

11. A system as claimed in any of claims 8 to 10 in which one sensor is operative to determine the card user's voice pattern and a second sensor is operative to determine the card user's fingerprint pattern.

12. A system as claimed in any of claims 9 to 11 in which the key card is electronically encoded with the reference values for the two physical characteristics, which reference values are read by the card reader and supplied to the comparator for comparison with the measured values.

13. A method of access control substantially as hereinbefore described with reference to the accompanying drawing.

14. An access control system substantially as hereinbefore described with reference to and as illustrated in the accompanying drawing.