GB2329498A

GB2329498A - Data carrier and method for controlling activation of a security feature

Info

Publication number: GB2329498A
Application number: GB9719876A
Authority: GB
Inventors: Steven John Heath
Original assignee: Motorola Ltd
Current assignee: Motorola Solutions UK Ltd
Priority date: 1997-09-19
Filing date: 1997-09-19
Publication date: 1999-03-24
Also published as: GB9719876D0

Abstract

A data carrier 10 is provided for use with a device e.g. cellular telephone. One of the carrier and the device has a security feature. The data carrier includes an interface 26, arranged for communicating with the device, a memory 22 arranged for storing at least one parameter 23, and a security agent 24 arranged for comparing an input parameter received from the interface with the stored parameter to provide a comparison value, and further arranged for processing the comparison value according to a set of rules, in order to derive a control signal. The control signal is used for controlling the activation of the security feature. For example, the parameter may be the time interval between first and second key actuations during entry of a PIN number, being compared with the previous such value. Temperature, pressure and call area codes can also be used.

Description

DATA CARRIER AND METHOD FOR CONTROLLING ACIIVATION OF A SECURITY FEATURE Field of the Invention This invention relates to data carriers, and particularly but not exclusively to data carriers for use in communication networks.

Background of the Invention Data carriers, such as smart-cards, are widely used with portable communications devices such as cellular telephones, to provide subscriber information and, amongst other things, security features.

For example, a SIM (subscriber information module) card for use with a cellular telephone may have an associated PIN (personal identification number), which a user must provide to the telephone in order to activate the SIM card and turn on the telephone, in order to make a call.

A problem with this arrangement is that if the telephone is stolen while switched on, or the PIN protection is either disabled or compromised, then the telephone can be used by an unauthorised person to make unwanted calls.

A further problem is that the unwanted calls are not typically detected at the time they are made, causing call charges which are borne either by the service provider or the subscriber.

Typically a SIM card is only blocked (disabled) once it has been reported stolen, or once a fraudulent call has been detected.

There is therefore a need to provide an improved security arrangement which reduces the likelihood of fraudulent calls. This invention seeks to provide a data carrier and method which mitigates the above mentioned disadvantages.

Summarv of the Invention According to a first aspect of the present invention there is provided a data carrier for use with a device, at least one of the data carrier and the device having a security feature, the data carrier comprising; an interface, arranged for communicating with the device; a memory arranged for storing at least one parameter; and, a security agent arranged for comparing an input parameter received from the interface with the stored parameter to provide a comparison value, and further arranged for processing the comparison value according to a set of rules, to derive a control signal; wherein the control signal is used for controlling the activation of the security feature.

Preferably the security agent is provided as software stored in the memory, for execution by a processor. Alternatively the security agent is provided as a logic circuit.

According to a second aspect of the present invention there is provided a method for controlling activation of a security feature of a device, comprising the steps of: storing a parameter in a memory; measuring an input parameter at an input; comparing the input parameter with at least one stored parameter to produce a comparison value; processing the comparison value using a set of rules to provide a control signal; and, controlling the activation of the security feature in dependence upon the control signal.

Preferably the set of rules are updated in dependence upon previous activity of the security agent. The input and stored parameters are preferably derived from an attribute of a user interface coupled to the input.

Alternatively the input and stored parameters are derived from an attribute of the device.

Preferably one or more of the at least one stored parameter is a previous input parameter, or is derived from a previous input parameter.

Preferably one or more of the at least one stored parameter is obtained from a remote source, the remote source being accessed via a communications network arranged for coupling to the device.

Preferably the at least one stored parameter relates to communications between the device and the network, the network being a cellular communications network and the device being a portable cellular communications device.

Preferably the at least one stored parameter includes information relating to selcted cells of the cellular communications network. The security feature preferably prevents operation of the device.

Brief Description of the Drawings An exemplary embodiment of the invention will now be described with reference to the drawing in which: FIG. 1 shows a preferred embodiment of a data carrier in accordance with the invention.

FIG. 2 shows a portable communications device incorporating the data carrier of FIG. 1.

FIG. 3 shows a flow diagram of a method incorporating the data carrier of FIG. 1.

Detailed Description of a Preferred Embodlment Referring to FIG. 1, there is shown a data carrier in the form of a smartcard 10 for use with a portable communications device. The smart-card 10 is credit-card sized, and contains an encapsulated circuit 20 and a transducer 30, such as a temperature sensor.

The encapsulated circuit 20 contains a memory 22, having a stored parameter 23 and a security agent 24, to be further described below. The encapsulated circuit 20 also includes a microprocessor 25 and an interface 26.

The security agent 24 is a software algorithm of the type known as an intelligent agent", which uses fuzzy logic and self-learning features. The security agent 24 operates according to a set of 'rules' which are contained within the algorithm, and which are used to determine the outcome of any operation performed. The rules are updated periodically by the security agent 24, as it 1earns' about the activities of the smart-card to. The security agent 24 uses the processor 25 in a semi-autonomous manner, and is arranged to take control of the processor 25 whenever necessary.

Referring now also to FIG. 2, there is shown a portable cellular telephone 40, having a display screen 41, a keypad 42 and a smart-card reader 45. The smart-card 10 is inserted into the smart-card reader 45. The smart-card 10 is arranged to communicate with the telephone 40 via the interface 26, which, when inserted into the smart-card reader 45, couples to internal terminals (not shown).

When switched on, the portable cellular telephone 40 operates at least partially under the control of the smart-card 10. A PIN number is stored in the memory 22. A start-up routine either within the memory 22 or within the telephone 40 may cause the cause the telephone 40 to be inoperable until the user has entered a series of numbers via the keypad 42, which correspond to the PIN number stored in the memory 22. If the correct number is not entered, use of the telephone 40 to make a call is prevented.

If the correct number has been entered, the telephone 40 can be used to make a call.

In a prior art arrangement, if the PIN number is compromised in some way, an unauthorised user could enter the correct PIN number and make a call.

In operation, and referring now also to FIG. 3, an enhanced security method is provided as follows. While entering a PIN number, a user presses a first key of the keypad 42 (block 110). The security agent 24 initiates a timer within the processor 25 (block 110). When a second key is pressed by the user (block 115) the timer is stopped (block 120). The time between the first and the second key presses is calculated (block 125).

A previous time period is stored in the memory 22, as parameter 23. This indicates the time between the first and the second key presses of a previous PIN number entry. The parameter 23 (and block 160) is compared with the calculated value (block 130). The security agent 24 then decides how the calculated value relates to the previous value (block 135), and provides a control signal indicating whether or not a suspicious situation has been detected. This decision could be based on a rigid comparison of the values, or it could incorporate a tolerance factor, provided by the rules of the algorithm within the security agent 24. In this way standard fuzzy logic methods and self-learning regimes within the security agent 24 can be used to provide a tolerance or weighting factor, such that the decision provides a good balance between minimum disruption for a legitimate user, and maximum possibility to prevent unauthorised use.

If the calculated time is greater than that allowed according to the rules, then further use of the telephone 40 is blocked (block 140). If the decision is that the calculated time is less than that allowed according to the rules, then the security agent 24 allows the telephone 40 to be used (block 145). The parameter 23 is then re-calculated, based on the previous parameter value 23 and the presently calculated value (block 150). The re-calculated parameter 23 is then stored in the memory 22, overwriting the previous value (block 155 and 160). The rules may also be updated, to take account of this activity.

In this way, if an unauthorised user obtains the PIN number for the smartcard, there is a good possibility that the unauthorised user may enter the PIN number appreciably slower than a legitimate user would, and the security agent 24 will recognise the much slower entry of the PIN number, and block, or at least temporarily disable the functionality of the telephone 40.

Other security features could be activated, other than a PIN number request, when suspicious operation of the telephone 40 is detected by the security agent 24.

For example, an alert message could be secretly sent to a remote site without the users knowledge, such as a base station of the communications network to which the telephone 40 is arranged to operate. This alert message could then be used by a service provider of the communications network, in order to call the telephone 40, such that an operator of the service provider then asks the user for a verification password or other verifying information about the user (date of birth, mother's maiden name, etc..) before allowing any further use of the telephone 40.

Alternatively, in response to suspicious activity, the security agent could request a second, longer PIN number,thus verifying that the user knows not only the first PIN, but a second, further PIN.

Embodiments may be envisaged, either in combination with, or as an alternative to the above. The telephone 40 may be switched on by a legitimate user, but then stolen by a thief while still switched on. In this case, the thief may not know the PIN number, but the telephone 40 can still be used to make calls until it is switched off. In this situation, the security agent 24 may be arranged to monitor a parameter other than the speed of keypad presses. In one example, the transducer 30 of the smart-card 10 is used to gather information from the environment in which the smart-card 10 is situated. The transducer may be a temperature or a pressure sensor.

The security agent 24 may be arranged to gather temperature readings, and to ask the user for the PIN number if a temperature reading is unusually high or low, for example.

In another example, information relating to calls could be used, such as the typical area codes used for past calls. An example of this would be a user who makes all calls to or within a particular city, such as London, England. In this case, all calls would, as of 1997, be preceded by the digits 0171 or 0181. The security agent 24 gathers call information, and the algorithm rules and the stored parameter then reflect that all calls begin with these digits. If a call is attempted which was not preceded by 0171 or 0181, the user would be asked for the PIN number, in order to verify that the user is authorised.

In this way, even if the telephone 40 is stolen while switched on, one or more security features may be invoked by the security agent 24, when suspicious activity is detected.

The security agent 24 may be arranged to use a number of different attributes, either singly or in combination, to detect suspicious activity. In addition to the keypad, temperature and call examples used above, other attributes may be used.

It will be appreciated that other embodiments to the one described above are possible. For example, the parameter 23 could be provided or at least influenced by the service provider of the communications network. It is also envisaged that a further security agent be provided at a base station of the communications network.

In this way the service provider may determine the level of security, perhaps in dependence upon the number of reported thefts of telephones.

Additionally the security agent of the service provider and/or the telephone 40 may gain information concerning the cells in which the telephone 40 has been used. In this way if a call attempted in a cell which has not previously been used by the telephone 40, one or more of the security features mentioned above is invoked by the security agent 24.

The smart-card could be provided without the transducer 30, or alternatively could be provided with an alternative inputloutput device.

It will also be appreciated that the above arrangement is not limited to smart-cards, but the security agent may also be incorporated directly within a portable communications device. Additionally, the above arrangement could be used with a smart-card for use in other applications, such as financial transaction cards and identity cards.

Furthermore, the security agent 24 need not be implemented in software. A hardware or firmware solution is also possible.

Claims

1. A data carrier for use with a device, at least one of the data carrier and the device having a security feature, the data carrier comprising; an interface, arranged for communicating with the device; a memory arranged for storing at least one parameter; and, a security agent arranged for comparing an input parameter received from the interface with the stored parameter to provide a comparison value, and further arranged for processing the comparison value according to a set of rules, to derive a control signal; wherein the control signal is used for controlling the activation of the security feature.

2. The data carrier of claim 1 wherein the security agent is provided as software stored in the memory, for execution by a processor.

3. The data carrier of claim 1 wherein the security agent is provided as a logic circuit.

4. A method for controlling activation of a security feature of a device, comprising the steps of: storing a parameter in a memory; measuring an input parameter at an input; comparing the input parameter with at least one stored parameter to produce a comparison value; processing the comparison value using a set of rules to provide a control signal; and, controlling the activation of the security feature in dependence upon the control signal.

5. The data carrier or method of any preceding claim, wherein the set of rules are updated in dependence upon previous activity of the security agent.

6. The data carrier or method of any preceding claim, wherein the input and stored parameters are derived from an attribute of a user interface coupled to the input.

7. The data carrier or method of any one of claims 1 to 6, wherein the input and stored parameters are derived from an attribute of the device.

8. The data carrier or method of any preceding claim, wherein one or more of the at least one stored parameter is a previous input parameter.

9. The data carrier or method of any preceding claim, wherein one or more of the at least one stored parameter is derived from a previous input parameter.

10. The data carrier or method of any preceding claim, wherein one or more of the at least one stored parameter is obtained from a remote source.

11. The data carrier or method of claim 10 wherein the remote source is accessed via a communications network arranged for coupling to the device.

12. The data carrier or method of claim 11, wherein the at least one stored parameter relates to communications between the device and the network.

13. The data carrier or method of claim 11, wherein the network is a cellular communications network and wherein the device is a portable cellular communications device.

14. The data carrier or method of claim 13, wherein the at least one stored parameter includes information relating to selected cells of the cellular communications network.

15. The data carrier or method of any preceding claim, wherein the security feature prevents operation of the device.