GB2425232A

GB2425232A - Inhibiting use of mobile device and SIM card

Info

Publication number: GB2425232A
Application number: GB0507280A
Authority: GB
Inventors: Richard Ormson
Original assignee: NEC Technologies UK Ltd
Current assignee: NEC Technologies UK Ltd
Priority date: 2005-04-11
Filing date: 2005-04-11
Publication date: 2006-10-18
Also published as: GB0507280D0

Abstract

A method of controlling the operation of a mobile radio communications device including a SIM card, the method including the step of receiving at the SIM card of the device a message arranged to initiate a control application serving to inhibit use of the mobile radio communications device which inhibition can comprise the locking of the SIM card and/or the device. A network operator may send the message to the handset 16 after theft of the handset has been reported 12. The message may be sent as an SMS message or via layer 3 signalling. After receiving the message, user data within the SIM card may be locked 18 and ultimately the handset itself may be deactivated 24. The initiating message may be deleted 26 and a confirmation message returned to the network 28.

Description

MOBILE RADIO COMMUNICATIONS

DEVICE AND RELATED METHOD OF CONTROL

The present invention relates to a mobile radio communications device and to a method of controlling the operation thereof so as, in particular, to inhibit use of the device and/or access to component elements thereof Handset security, both in terms of access to the data stored within the handset, and prevention of use of the handset itself, for example, after theft, is becoming an increasingly important issue.

While security mechanisms have been provi'ded in relation to mobile radio communication devices such as cellular phone handsets, it is found that such mechanisms however suffer limitations and can only offer a restricted level of security For example, and in accordance with existing security systems, if a cellular phone handset is stolen, its owner will typically notify their network operator either directly or via a third party such as the relevant police authorities. Such notification will include identifying the number of the handset stolen.

Upon receiving notification of the handset, the network operator can immediately place a "call-bar" in relation to the subscribed identity code, hereinafter referred to as the Subscriber Identifier Module (SIM) associated with that particular user's telephone number Such a call-bar prevents any calls (except for emergency calls) being made from a handset using that SIM card. The basis for this operation is that the SIM is referenced by way of an International Mobile Subscriber Identity (1MSI) number which is built into the SIM itself The network operator already has knowledge of the IMSI for the particular user's SIM since it is stored in the network operator's billing database to ensure that calls originating in association with that SIM are billed to the correct user In addition to identifying, and subsequently barring, use of the SIM associated with the stolen handset, it can also prove possible to place a bar on use of the handset itself However, this further security measure requires that the user's handset serial number, i e the so-called International Mobile Equipment Identity (]1MIEI), is registered on a stolen handset register such as the Central Equipment Identity Register (CEIR) When so registered, any subsequent attempt to connect the handset to a network that itself references the CEIR can therefore readily be prevented and so the handset can be rendered useless in relation to such a network. However, the reporting of the IMEI requires first that the user or network operator knows the relevant IMEI.

Since such data is not required for billing purposes, it has been found that network operators have generally shown little interest in recording that identifier Further, the identifier generally has little practical use to users and so, historically, users have not generally become aware of, or recorded it either.

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As will be appreciated, once the call-bar has been set up in relation to a particular SIM, regardless of the cellular phone handset that the SIM is used with, the SIM will not then be useable Should an attempt be made by the thief to replace the SlIM but continue to use the stolen cellular phone handset, such use will not be possible on any network that references the CEIR While the above-mentioned measures offer some degree of security, limitations are nevertheless experienced since the potentially large amount of user- related data stored on the SIM is still readily accessible to a thief and, further, the handset itself will still be usable with another SIM when connected to a network that does not reference the CEIR The present invention seeks to provide for a method of controlling a mobile radio communications device, and such a mobile radio communications device, having advantages over known such methods and devices According to one aspect of the present invention, there is provided a method of controlling the operation of a mobile radio communications device including a SIM card, the method including the step of receiving at the SlIM card a message arranged to initiate a control application serving to inhibit use of the mobile radio communications device The invention is particularly advantageous in that through employing signalling arising from the network subsequent to the theft of the device, the use of the device can be inhibited by the locking of the SIM card so as to not only prevent use thereof, but also to prevent access to data stored therein.

The invention is therefore particularly attractive to handset users insofar as it can serve to protect personal data stored on the SIM card, and also to network operators since it makes the initial theft of a mobile radio communications device less attractive Thus, the application preferably seeks to lock data within the SIM card

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Further, the message sent from the network to the device can advantageously include a device identifier and, in this manner, the device can be arranged to receive the said identifier and then to compare it with its own device identifier Advantageously, inhibition of use of the device, or at least inhibition of access to data stored therein, can then be initiated on the basis of the result of such comparison.

Advantageously, the said inhibition of use of the device comprises the locking of data therein so as to prevent access by a thief. As an alternative, or in addition, such inhibition can comprise the mere deactivation of the handset so as to prevent subsequent use of the stolen handset It should be appreciated that the present invention can also provide for a computer program comprising computer program code means adapted to perform of the steps of the method as defined above In particular, the aforesaid computer program can advantageously be embodied on a computer readable medium Yet further, the invention can include the step of sending the said message from the network to the mobile radio communications device upon receiving notification of the theft of a device including the said SIM card Advantageously, the method also includes the step of identifying the mobile radio communications device associated with the said SIM card.

Alternatively, the method of the present invention can include the step of sending the message to the SIM card identified as being used within a mobile radio communications device reported as stolen.

Preferably, the handset is identified by way f a user equipment register.

This further aspect of the present invention therefore advantageously involves a network operator ascertaining the IMEI currently associated with the IMSI so as to identify if it is the stolen device associated with that user ID Data on IMIEI is already present within the network layer 3 signalling, so the register could be automatically built by the network Alternatively the system may rely on the user entering their own details on one of the web sites that operators have already provided for this purpose Given that the operator has this data, the message can then be readily sent to the SIM card represented by that particular IMS1 and in a manner similar to that outlined above The signalling sent to the mobile radio communications device is advantageously sent as part of the layer 3 signalling or, alternatively in the form of

SMS

Yet further, the method can advantageously include the step of deleting the initiating message, and also preferably any control keys contained therein and this can advantageously limit the ability of a party attempting to reverse the locks in place Still further, the method can also include the transmission of a message from the device back to the network confirming the locking and/or deactivation of the device and/or the SlIM card.

According to another aspect of the present invention, there is provided a mobile radio communications device arranged for operation with a SIM card and arranged to receive a message transmitted from a network to the said SIM card, wherein the said message is arranged to initiate an application serving to inhibited use of the mobile radio communications device.

Yet further, the present invention can provide for a SIM card arranged to receive a message from a network to a mobile radio communications device within which it is mounted, wherein subsequent to receipt of an appropriate message, the SIM card can initiate an application serving to inhibit use thereof, and/or use of the device within which it is mounted / It should of course be appreciated that the present invention can be 1 5 advantageously employed in addition to the current security measures such as call- barring.

The invention is described further hereinafter, by way of example only, with reference to the accompanying drawings in which Fig. 1 is a flow diagram illustrating a control method according to one embodiment of the present invention, Fig 2 is a flow diagram illustrating a control method according to another aspect of the present invention; and Fig 3 is a schematic block diagram of a mobile radio communications device in the form of a cellular phone handset arranged for use in accordance with the present invention Turning first to Fig 1, there is provided a flow diagram illustrating a method of controlling access to a cellular phone handset and comprising one embodiment of the present invention For completeness, the method as illustrated includes the step of identifying, and notifying the theft of a handset although these aspects do not of course form part of the method of the present invention Thus, with regard to Fig 1, at step 10, the initial theft of the cellular phone handset is identified and then reported, either indirectly via the police, or directly to the network operator at step 12 At step 14 the network operator identifies the S1M card associated with the user who's handset has been stolen and, having identified the associated IMSI number, sends, at step 16, a message to the handset with the SIM card mounted therein If the SIM card of the stolen handset is stiir connected to a network, or indeed if it re-appears on a network later, the network operator can readily send a message to it Such a message is advantageously sent via layer 3 signalling although, as an alternative, it could be sent as a SMS It is considered that the use of SMS has advantages over layer 3 signalling in as much as the mechanism for the signal routing to the SIM card is inherently present in the SMS standards. Also, SMS will function correctly regardless of the network to which the SIM card is connected, while layer 3 signalling is likely to require an additional mechanism to achieve such common functionality across a variety of networks.

Turning to step 16 within Fig. 1, when received at the SIM card of the handset that has been stolen, the message serves to activate a SIM toolkit application. Further, the message can be arranged to contain flags to indicate if the SIM card and/or the handset are to be locked, in addition to optional fields such as the IMIEI of the handset that was stolen at the same time as the theft of the SIM card was notified and also a variety of general lock keys which can be generated on per case basis and are stored by the originating network.

The SIM toolkit application is advantageously arranged to perform three main functions First, and as occurring at step 18, user data within the SIM card is locked if a "lock SIM" flag is set within the message. The lock can be arranged to be irreversible and this is generally considered to be a preferred mode of operation since any SlIM cards recovered after theft are unlikely to be re-used However, if locking of the SlIM card is to be reversible, a known key is then arranged to be used when performing the lock and to support such operation the optional inclusion of keys in the initiating message is provided for Secondly, if an IM1EI was given within the initiating message, and an open "lock handset" flag was set, the SIM toolkit is arranged at step 20 to compare the IMEI within the initiating message to the IMEI of the handset in which the SJM is mounted. It is advantageously found that such reading of the IMEI by the SlIM card is a standard function and so, advantageously, no new messaging need be required. If the two IMIEIs being compared match, the SIM toollut is then advantageously arranged to perform two further functions indicated at steps 22 and 24. That is, at step 22, user data can be locked within the handset and/or at step 24 the handset itself can be deactivated to prevent further use With regard to the locking of the user data within the handset, a handset software adaptation may be required to support such an operation and in some handsets a user data lock can be tied to the SIM user lock As with the S1M data discussed above, the lock may be reversible or irreversible. Again, the reversible version will require a known lock key to be used With regard to deactivation against further use at step 24, there is a variety of ways of achieving this as discussed further below and any method that can be accessed from the SIM is considered to be suitable. Again, the deactivation method can be reversible or irreversible although, in this instance, it is likely that the reversible option might be preferred since handsets are generally more expensive than SIM cards and are more likely to be re-used if recovered after theft A subsequent step that can be taken in accordance with this embodiment of the present invention indicated at step 26 is that the initiating message can be deleted from the handset Such deletion also involves removal of all of the keys contained therein and this can advantageously serve to limit useful data available to anyone attempting to reverse locks.

As an optional feature of the method illustrated in association with Fig. 1, and as indicated at step 28 a message can be returned to the network confirming that the SIM and/or the handset has been locked and/or deactivated A second embodiment of the present invention is illustrated by way of Fig 2.

This second embodiment allows for handset-only locking and can be readily used in a situation where a stolen handset is found to be used but without the original SIM card Turning therefore to Fig 2, there is again illustrated at initial step 30 that handset theft has occurred, along with the subsequeflt reporting at step 32 of the theft to the network operator either directly or via the appropriate police authorities.

This aspect of the present invention generally requires the IMIET of the handset to be known for inhibiting action to be taken if the stolen handset is still operating on a CEIR connected network, or re-appears on such a network. With the IMEI of the stolen handset is added to the stolen equipment register as at step 34, the network operator can then readily ascertain the IMSI currently associated with that IMEI since such data will be present in network layer 3 signalling The network operator can then readily send a message to the SIM card represented by the identified IMSI in the manner described in relation to Fig 1 and as indicated at steps 36 and 38 of Fig 2.

When received at the SIM card, the message serves to activate a SIM toolkit application similar to that discussed in relation to Fig. 1. The message is advantageously of the same format but may of course have different flags set and

different optional fields included

With regard to the Fig. 2 embodiment however, the toolkit operation which is initiated at step 40 is arranged to perform the following functions First, at step 42 the user data within the SIM card is locked if the "lock SIM" flag is set within the message In this case this is unlikely to be used since the SIM card may well be legitimate Secondly, and as indicated at step 44, and particularly since there will be some degree of certainty that the [MEl contained within the message will match that of the handset, the "lock handset" flag will be set Thus, the SIM toolkit can arrange for a comparison of the IMEI within the message with that of the IMEI of the handset in which the S1M card finds itself and once the expected match is found, the handset can be deactivated at step 44 and/or have data locked therein as illustrated at step 46.

Further, and as with the Fig I embodiment, a step of deleting the initial message, as shown at step 48, along with any of the keys contained therein, can also be provided for so as to limit use of the data and to prevent reversal of the locks

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Finally, and as illustrated at step 50, a message can be returned to the network confirming that the said de-activation and/or data locking has been completed.

With regard to both Figs. 1 and 2, it will be appreciated that one particular outcome of the method of the invention is that de-activation of the handset might be required There is a variety of de-activation mechanisms that are suitable for the present invention although it should be appreciated that the invention is not restricted to any one or more of these. As examples however the handset de-activation could involve any one or more of the following The first example involves use of the existing SIM lock mechanism, which will be defined in standards, wherein the handset is locked to a particular SIM. By locking to the current SIM, which has just been de-activated by the network operator, the handset is also then deactivated This method has the advantage that it is already almost entirely supported and only alterations are required to allow the lock to be activated by the SIM toolkit, with the majority of the existing handset software unchanged However the S1M lock generally comprises a reversible lock, so this may not prove to be the most secure manner of deactivating the handset. Also it will not generally prove useful in the scenario outlined above in which the handset is being used with a new SIM While as noted SlIM deactivation could still be carried out, this can prove commercially problematic since the SIN'! itself may not have been stolen A second example involves the corruption of the handset software by overwriting part of the handset memory This will in turn activate the tamper protection mechanisms and so render the handset inoperative. Again this can be readily implemented, as application level commands to write to memory are already present in most handsets The method of the invention then merely makes these accessible to the SlIM toolkit If implemented alongside appropriate code protection mechanisms it can advantageously prove very difficult for anyone other than the handset manufacturer to reverse this deactivation method.

A third example involves the implementation of an additional new lock mechanism. It is appreciated that there are many known ways of rendering a device inoperative through use of software or hardware locks, and many of these can be applied to this scenario Any method that allows operations to be prevented or limited in response to an external command can be considered suitable and methods that include steps to make reversing the process difficult for unauthorised persons to achieve are preferred. Most such methods exhibit greater complexity than the ones indicated above, since they are not already present in the handset Turning now to Fig 3, there is illustrated in bock schematic form, a mobile radio communications device 50 such as a cellular phone handset 52 arranged for use in accordance with the present invention Only the basic functionality of the device is illustrated and so shown in relation to the cellular phone handset 52 is an antenna 54 and associated transmissionlreception circuitry 56 for standard operation Also, processing functionality 58 is provided along with an associated memory functionality 60 for use in association with a SlIM card 62 which is specific to a particular user and operatively mounted in a standard manner onto the device The handset 52 is arranged to operate in accordance with the method discussed above such that,upon receipt of an appropriate message from the network, a SIM toolkit application can he initiated serving to execute the security features discussed above Thus, through messaging originating from the network, the operation of the SIM card and a handset can be inhibited as required so as to make theft of the handset less attractive and also to limit the benefit that a thief might obtain from a theft that does occur With regard to such devices embodying the present invention, the S1M card itself and the overall method of operation, it should be appreciated that the level of security required and the security methods already implemented on the handset will determine the choice of deactivation method. Howver almost any such method can be made compatible with the overall system of remote deactivation 1 5 Once the security procedure has been followed, the user data can be rendered secure and the handset can be rendered no longer useable While activation of these security provisions requires use of the handset on a network, this is unlikely to prove a limiting feature since, once stolen, and to retain value, the handset has to be shown working to the would-be purchaser The simplest way to do this is to turn it on with the original SIM still in place. Thus, there is a very high likelihood that the stolen handset will be activated at least once with the original SIM still inserted Also, if the theft is reported quickly enough, the handset may not yet have been turned off If the stolen S1M is used in a different handset to that in which it was mounted at the time of theft, then the procedure is likely only to apply in part since while the user data in the SIM will be locked, the stolen handset may not be deactivated in view of possible commercial and legal problems One particular advantage of the present invention is that the provision of the toolkit feature within a SIM card is unlikely to carry any great cost implication for manufactures and network operators and so matters of economics should not prevent wide adoption of the invention An important aspect of the present invention is that it can provide a security mechanism that operates regardless of whether or not the network accessed by the stolen SIM is within the CEIR group Also, since it can be implemented with minimal change to existing handset architecture the method of the invention offers a security solution that is preferable to those proposed by the GSMA to address areas outside CEIR coverage, that is so-called "regional lock" mechanisms.

The invention therefore offers a level of security that can be considered as least as effective as the alternative systems proposed by GSMA, while exhibiting for greater simplicity for implementation by handset manufacturers

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Claims

1 A method of controlling the operation of a mobile radio communications device including a SIM card, the method including the step of receiving at the SIM card of the device a message arranged to initiate a control application serving to inhibit use of the mobile radio communications device 2. A method as claimed in Claim 1 wherein the control application serves to lock data within the Shy! card so as to inhibit use of the device.

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3 A method as claimed in Claim 1 or 2, and including the step of identifying the mobile radio communications device associated with the said SIM card 4. A method as claimed in Claim 3, wherein the message sent from the network to the device can advantageously include a device identifier 5 A method as claimed in Claim 4, and including the step of comparing the device identifier received with the message with an identifier associated with the device 6. A method as claimed in Claim 5, wherein the said inhibition of use of the device is initiated on the basis of the result of such comparison.

7 A method as claimed in any one or more of the preceding claims wherein the said inhibition of use of the device comprises the locking of data therein 8. A method as claimed in any one or more of the preceding claims wherein the said inhibition comprises deactivation of the device 9 A computer program comprising computer program code means adapted to perform the steps of the method as defined in any one or more of the preceding claims 10. A computer program as defined in Claim 9 and embodied on a computer readable medium II A method as claimed in any one or more of Claims ito 8 and including the step of sending the said message from the network to the mobile radio communications device upon receiving notification of the theft of a device including the said SIM card 12 A method as claimed in any one or more of Claims Ito 8, and including the step of sending the message to the SIM card as identified as being used within a mobile radio communications device reported as stolen.

13 A method as claimed in Claim 12, wherein the handset is identified by way of a stolen equipment register.

14 A method as claimed in Claim 13, and including the step of ascertaining the IMSI currently associated with the IMFI so as to identif' the stolen device from the stolen equipment registered A method as claimed in any one or more of Claims 1 to 8 and II to 14 wherein the signalling sent to the mobile radio communications device is sent as part of the layer 3 signalling.

16 A method as claimed in any one or more of Claims I to 8 and 11 to 14 wherein the signalling sent to the mobile radio communications device is sent as SMS.

17 A method as claimed in any one or more of Claims Ito 8 and 11 to 16, and including the step of deleting the initiating message.

18. A method as claimed in any one or more of Claims ito 8 and 11 to 17, and including the step of transmitting a message from the device back to the network confirming the locking and/or deactivation of the device and/or the SIM card 19 A mobile radio communications device arranged for operation with a SIM card and arranged to receive a message transmitted from a network to the said SIM card, when the said message is arranged to initiate an application serving to inhibited use of the mobile radio communications device 20 A device as claimed in Claim 19, wherein the application is arranged to lock data within the SIM card so as to inhibit use of the device.

21 A device as claimed in Claim 19 or 20, and arranged to receive a device identifier within the message sent from the network and for comparing the said received device identifier with an identifier associated with the device for the comparison thereof 22 A device as claimed in Claim 21, and arranged such that the said inhibition of use of the device is initiated on the basis of the result of the said comparison 23 A device as claimed in any one or more of Claims 19-22, and arranged such that the inhibition use of the device comprises the locking of data therein 24 A device as claimed in any one or more of Claims 19-23, and arranged such that the said inhibition comprises deactivation of the device.

25. A device as claimed in any one or more of Claims 19-24, wherein the said application comprises a SIM toolkit application 26 A SIM card arranged to receive a message from a network to which a mobile radio communications device within which it is mounted is connected, wherein subsequent to receipt of an appropriate message, the SIM card can initiate an application serving to inhibit use thereof, and/or use of the device within which it is mounted.

27 A SIM card as defined in Claim 26 and arranged for use within a mobile radio communications device as defined in any one or more of Claims 20-25 28 A method of controlling operation of the mobile radio communications device substantially as hereinbefore described with reference to, and as illustrated in, Fig 1 and Fig 2 of the accompanying drawings 29 A mobile radio communications device substantially as hereinbefore described with reference to, and as illustrated in, Fig. 3 of the accompanying drawings A SIM card substantially as hereinbefore described with reference to the accompanying drawings.