GB2461401A

GB2461401A - Mobile device security

Info

Publication number: GB2461401A
Application number: GB0911620A
Authority: GB
Inventors: Brian Joseph Fascione; David Brophy
Original assignee: UNIVERSAL SYSTEMS SOLUTIONS
Current assignee: UNIVERSAL SYSTEMS SOLUTIONS
Priority date: 2008-07-04
Filing date: 2009-07-06
Publication date: 2010-01-06
Also published as: WO2010001180A3; GB0911620D0; GB0812285D0; WO2010001180A2

Abstract

A method, computer program and mobile device are disclosed in which the security of data on the device is increased. The computer program running on the device intercepts messages, for example SMS messages, and determines whether the message contains a command or is simply a message. Messages are passed to the normal message depository to be viewed by the user of the device, whilst commands result in actions being taken by the mobile device. Such actions include deletion of all or part of the data on the device, instigating tracking of the device and locking of the device. On replacement of a SIM card in the device, a message is sent froth the device indicating the change of SIM card and providing details of the new SIM card. Properties of the mobile device can be monitored and a message sent if the value of the property is within a specified range.

Description

MOBILE DEVICE SECURITY

FIELD OF THE INVENTION

This invention relates to mobile device security. In particular, the invention enables discreet monitoring and remote process control of mobile devices, including mobile telephones.

BACKGROUND

Mobile devices, in addition to making and receiving telephone calls, are able to send and receive data, including, for example, text messages (SMS messages) and email. Mobile devices may also have a large data storage capacity for storing SMS messages, emails, electronic documents, contact telephone numbers, contact email addresses, event logs, passwords and other data. Mobile devices may therefore be used to store various types of information belonging to a user. In the event of the loss or theft of a mobile device, there is the possibility that the information stored on the mobile device may be stolen or misused, or that confidential information may be distributed.

When a mobile device is stolen, a thief often changes the SIM card of the device, such that the device uses a different telephone number for communication. This may prevent a stolen device from being tracked.

There is therefore a need for a system and method to improve the security of data stored on a mobile device. There is also a need for a system and method to improve the tracking and monitoring of mobile device. To be effective, such systems must not interfere with the normal operation of the mobile device, and must be hidden from a user to prevent the system being shut down or otherwise rendered inactive.

SUMMARY OF THE INVENTION

Preferred embodiments of the present invention seek to provide solutions to the above-

described problems associated with the prior art.

According to a first aspect of the present invention, there is provided a method to be implemented on a mobile device, the method comprising the steps of receiving a message from a remote device; analysing the message to determine whether said message contains an instruction; and processing the message, the step of processing the message including, if the message contains an instruction, extracting the instruction from the message and passing the instruction to an instruction processing means of said mobile device, and, if the message does not contain an instruction, passing said message to a message register meafis of said mobile device.

An advantage of this method is that it enables a host device to send instructions to a mobile device using an existing messaging service, for example SMS or email. Instead of routing a message received by the device directly to a message registry means, a message is first analysed to determine whether it contains an instruction. The message processing depends on whether the message contains an instruction. If the message contains an instruction, the instruction is extracted and passed to an instruction processing means. If the message does F not contain an instruction, it is passed to the usual message registry means. F The method may comprise the further step of, if the message contains an instruction, verifying the source of the message, wherein an instruction contained in a message is passed to the instruction processing means for processing if and only if the source verification is successful.

The advantage of this step is that only authorised remote devices may remotely control a process on the mobile device, by sending an instruction encoded in a message.

Preferably, if the message contains an instruction, the message is not passed to the message register means of the mobile device.

S A user is therefore not alerted that the mobile device has received an instruction from a remote device. This enables remote control of various processes on the mobile device to be carried out discreetly.

Preferably, if the message contains an instruction, the message is deleted after extraction of the instruction.

Automatic deletion of messages ensures that a user would not discover a message containing an instruction, which might alert a user to the fact that the mobile device was being sent instructions from a remote device. The storage capacity of the mobile device is not used for storing instruction-containing messages.

The method may comprise the further step of said instruction processing means receiving and processing the instruction.

The mobile device may, if the instruction is to destroy data stored on the mobile device, delete data stored on the mobile device.

Thereby, if a mobile device is lost or stolen, data stored on the mobile device may be deleted by sending an instruction to delete data from a remote device.

Preferably, the data deleted by the mobile device includes at least one of: messages stored on the mobile device; emails stored on the mobile device; user-defined data stored on the mobile device; electronic documents stored on the mobile device.

Thus the mobile device may be pre-configured to delete specific data, or an instruction may specify the data to be deleted, in response to an instruction received from the remote device. Advantageously, this prevents data stored in a mobile device fi-om being stolen and/or misused, and prevents the distribution of confidential data.

In response to an instruction containing configuration settings, the mobile device may update one or more configuration settings stored on the mobile device, in accordance with the instruction.

Thus, the settings on the mobile device can be updated remotely by sending a message to the mobile device. For example, the remote device may specify a new telephone number to be used by the mobile device to communicate with the remote device.

The remote device may, in response to an instruction containing a function status, enable or disable a function of the mobile device in accordance with the instruction.

Thus, when a function is no longer required, it can be disabled remotely by sending a message to the mobile device. For example, it may be no longer necessary for the mobile device to monitor and report certain events to the remote device. Or, it may no longer be required for the mobile device to process certain instructions.

If the mobile device includes a GPS receiver, the remote device may, in response to an instruction requesting location data, switch on the GPS receiver and receive UPS data relating to the location of the mobile device.

Thus the remote device can control whether the mobile device receive GFS data specifying its location. This enables the mobile device to be tracked by the remote device.

If the mobile device includes a speaker, the mobile device may, if the instruction is to identify the mobile device, causes the loud speaker to emit an alarm.

This can be used by a user to locate the mobile device if it has been mislaid nearby.

The mobile device may set the loud speaker volume to maximum before emitting an alarm.

This ensures that the alarm is heard, even if the volume is set to low, or muted.

S

The method may fttrther comprise the step of sending a message to the remote device in response to the instruction.

This enables a remote device to receive information from the mobile device.

In response to an instruction requesting information, the message sent to the remote device may contain information requested by the remote device. This also enables a remote device to obtain information from a mobile device which has been newly added to the system, or for which a monitoring frmnetion or instruction processing flmction has been newly enabled.

An advantage of this feature is that a remote device may request information from the mobile device in order to update its records relating to the mobile device.

The message sent to the remote device may contain at least one of: data relating to the location of the device; configuration data stored on the mobile device; and data stored on the SIM card of the mobile device.

This enables the remote device to monitor the location of the device, to check whether settings of the mobile device have been updated, and to check whether the SIM card has changed.

The message sent to the remote device may confirm that the instruction has been processed.

Thus the remote device may be informed whether instruction processing has successfully completed.

Preferably, the message sent to the remote device is not stored on the mobile device.

This enables the remote device to receive information discreetly from the mobile device, without this becoming known to a user.

Preferably, the step of processing of the instruction overrides any other program running on the mobile device.

This ensures that the processing of the instruction takes priority over any other program and is not delayed by any other program.

The method may thither comprise the steps of monitoring at least one property of the mobile device; and sending a reporting message to the remote device when the value of said at least one property of the mobile device is within a specified range.

This feature enables a remote device to be automatically informed of changes to the value of a monitored property.

The step of sending a message to a remote device may include encoding the value of said at least one property of the mobile device in said reporting message and sending said reporting message to the remote device.

This enables a remote device to be automatically informed when a monitored property changes.

Preferably, a reporting message is sent to the remote device only if a monitor status of the mobile device is active.

Thus the step of sending a reporting message to the remote device may be disabled if it is not required.

Preferably, the reporting message sent to the remote device is not stored on the mobile device.

This enables the remote device to monitor the mobile device discreetly, without alerting a user of the mobile device.

The at least one the property monitored may include at least one of: an identification code associated with the SIM card loaded into the mobile device; the power level of the mobile device; and the location of the mobile device.

A lost mobile device may thereby be located by location data sent to the remote device; if a monitored mobile device is about to lose power, the remote device is informed; if a SIM card is changed, the remote device is automatically informed, enabling it to retain a communication link with the mobile device.

The at least one property may be monitored continuously.

The at least one property may be monitored at specified intervals.

The at least one property may be monitored each time that the mobile device is powered on.

A message may be an SMS message.

The advantage of this feature is that the remote device can monitor the mobile device using an existing messaging program, wherein the messages sent by the remote device to the mobile device (e.g. messages containing instructions), and messages sent by the mobile device to the remote device (e.g. responses to instructions and reporting messages), are SMS messages.

According to a second aspect of the invention, there is provided a method to be implemented by a mobile device, for enabling remote monitoring of the mobile device by a remote device, the method comprising the steps of: monitoring at [east one property of the mobile device; and sending a message to a remote device when the value of at least one property of the mobile device is within a specified range.

S The method may comprise the further step of sending a message to a remote device includes encoding the value of said at least one property of the mobile device in said message and sending said message to the remote device.

Preferably, a message is sent to the remote device only if a monitor status of the mobile device is active.

The at least one the property monitored may include at least one of: an identification code associated with the SIM card loaded into the mobile device; the power level of the mobile device; and the location of the device.

The at least one property may be monitored continuously.

The at least one property may be monitored at specified intervals.

The at least one property may be monitored each time the mobile device is powered on.

A message may be an SMS message.

According to a third aspect of the invention, there is provided a method to be implemented on a mobile device adapted to communicate with a remote device through a mobile communications link, the method comprising the steps of: receiving a message from a remote device; analysing the message to determine whether said message contains an instruction; processing the message, the step of processing the message including, if the message does not contain an instruction, passing said message to a message register means of said mobile device; and, if the message contains an instruction, extracting the instruction from the message and passing the instruction to an instruction processing means of said mobile device, the instruction processing means carrying out the step of deleting data stored on the mobile device; monitoring an identification code associated with the SIM card loaded into the mobile device; and sending a reporting message to the remote device if the SIM card is changed, the reporting message including the identification code of the new SIM card; wherein the message received from the remote device and the reporting message sent to the remote device are SMS messages.

According to a fourth aspect of the invention, there is provided a program comprising computer program code adapted, when said program is loaded onto a mobile device, to make the mobile device execute the steps of: receiving a message from a remote device; analysing the message to determine whether said message contains an instruction; and processing the message, the step of processing the message including, if the message contains an instruction, extracting the instruction from the message and passing the instruction to an instruction processing means of said mobile device, and, if the message does not contain an instruction, passing said message to a message register means of said mobile device.

The program may be adapted to make the mobile device execute the further step of, if the message contains an instruction, verifying the source of the message, wherein an instruction contained in a message is passed to the instruction processing means for processing if and only if the source verification is successful.

The program may be adapted to make the mobile device execute the step of said instruction processing means receiving and processing the instruction.

Preferably, if the instruction is to destroy data stored on the mobile device, the mobile device deletes data stored on the mobile device.

Preferably, the data deleted by the mobile device includes at least one of: messages stored on the mobile device; emails stored on the mobile device; user-defined data stored on the mobile device; and electronic documents stored on the mobile device.

Preferably, in response to an instruction containing configuration settings, the mobile device updates one or more configuration settings stored on the mobile device, in accordance with the instruction.

Preferably, in response to an instruction containing a function status, the remote device enables or disables a function of the mobile device in accordance with the instruction.

The mobile device may include a UPS receiver, and preferably, in response to an instruction requesting location data, the remote device switches on the UPS receiver and receives UPS data relating to the location of the mobile device.

The mobile device may include a speaker and, preferably, if the iostruction is to identify the mobile device, the mobile device causes the loud speaker to emit an alarm.

The program may be adapted to make the mobile device execute the step of sending a message to the remote device in response to the instruction.

In response to an instruction requesting information, the message sent to the remote device may contain information requested by the remote device.

The message sent to the remote devicc may confirm that the instruction has been processed.

The program may be adapted to make the mobile device execute the further steps of: monitoring at least one property of the mobile device; and sending a reporting message to the remote device when the value of said at least one property of the mobile device is within a specified range.

The at least one property may be monitored continuously.

The at least one property may be monitored at specified intervals.

According to a fifth aspect of the invention, there is provided a program comprising computer program code adapted, when said program is loaded onto a mobile device, to make the mobile device execute the steps of: monitoring at least one property of the mobile device; and sending a message to a remote device when the value of at least one property of the mobile device is within a specified range.

The step of sending a message to a remote device may include encoding the value of said at least one property of the mobile device in said message and sending said message to the remote device.

The at least one property may be monitored continuously.

The at least one property may be monitored at specified intervals.

S

Preferably, a message is an SMS message.

According to a sixth aspect of the invention, there is provided a program comprising computer program code adapted, when said program is loaded onto a mobile device, to make the mobile device execute the steps of: receiving a message from a remote device; analysing the message to determine whether said message contains an instruction; processing the message, the step of processing the message including, if the message does not contain an instruction, passing said message to a message register means of said mobile device; and, if the message contains an instruction, extracting the instruction from the message and passing the instruction to an instruction processing means of said mobile device, the instruction processing means carrying out the step of deleting data stored on the F mobile device; monitoring an identification code associated with the SIM card Loaded into the mobile device; and sending a reporting message to the remote device if the SIM card is changed, the reporting message including the identification code of the new SIM card; wherein the message received from the remote device and the reporting message sent to the remote device are SMS messages.

According to a seventh aspect of the invention, there is provided a mobile device adapted to communicate with a remote system by sending and receiving messages through a mobile communications network, the mobile device comprising: a message analysis means, adapted to determine whether a message received from a remote device contains an instruction, and to extract an instruction from a message determined to contain an instruction; a processing means, adapted to receive and process instructions extracted by the message analysis means; and a message registiy, for receiving messages determined by the message analysis means not to contain an instruction, wherein said message analysis means is adapted to pass a message to the message registry if said message is determined by the message analysis means not to contain an instruction.

The message analysis means may be adapted to verify the source of a message received from a remote device, and to pass an instruction contained in the message to the instruction processing means if and only if the source verification is suceessftil.

The message analysis means may be adapted to pass a message to the message registry if and only if the message has been determined not to contain an instruction.

The message analysis means may be adapted to delete a message determined to contain an instruction, after extraction of the instruction.

The instniction processing means may be adapted to delete data stored on the mobile device if an instruction to destroy data is received from a remote device.

Preferably the data deleted by the mobile device includes at least one of: messages stored on the mobile device; emails stored on the mobile device; user-defined data stored on the mobile device; electronic documents stored on the mobile device.

The instruction processing means may be adapted, in response to an instruction containing configuration settings, to update one or more configuration settings stored on the mobile device, in accordance with the instruction.

The instruction processing means may be adapted, in response to an instruction containing a function status, to enable or disable a function of the mobile device in accordance with the instruction.

The mobile device may further comprise a GPS receiver, and be adapted, in response to an instruction requesting location data, to switch on the GPS receiver and receive GPS data relating to the location of the mobile device.

The mobile device may further comprise a loud speaker, and be adapted, if the instruction is to identif3, the mobile device, to cause the loud speaker to emit an alarm.

The mobile device may be adapted to set the loud speaker volume to maximum before emitting an alarm.

The instruction processing means may be adapted to send a message to the remote device in response to an instruction.

The message sent to the remote device may contain information requested by the remote device.

The message sent to the remote device may contain at least one of data relating to the location of the device; configuration data stored on the mobile device; and data stored on the SIM card of the mobile device.

The instruction processing means may be adapted to send a confirmation message to the remote device after processing of the instruction.

The instruction processing means may be adapted to override any other program running on the mobile device.

The mobile device may be further adapted to monitor at least one property of the mobile device and to send a reporting message to the remote device when the value of said at least one property of the mobile device is within a specified range.

The mobile device may be further adapted to send a reporting message encoding the value of said at least one property of the mobile device to the remote device.

S The mobile device may be adapted to send a reporting message to the remote device only if a monitor status of the mobile device is active.

The mobile device may be adapted to monitor said at least one property continuously.

The mobile device may be adapted to monitor said at least one property at specified intervals.

The mobile device may be adapted to monitor said at least one property each time the mobile device is powered on.

A message may be an SMS message.

According to a eighth aspect of the invention, there is provided a mobile device adapted to communicate with a remote system by sending messages through a mobile communications network, the mobile device being adapted to monitor at least one property of the mobile device, and to send a message to the remote device when the value of said at least one property of the mobile device is within a specified range.

The mobile device may be further adapted to send a message encoding the value of said at least one property of the mobile device to the remote device.

The mobile device may be adapted to send a message to the remote device only if a monitor status of the mobile device is active.

A message may be an SMS message.

According to a ninth aspect of the invention, there is provided a mobile device adapted to communicate with a remote system by sending and receiving messages through a mobile communications networlc, the mobile device comprising: a message analysis means, adapted to determine whether a message received from a remote device contains an instruction, and to extract an instruction from a message determined to contain an instruction; an instruction processing means, adapted to receive and process instructions extracted by the message analysis means; the instruction processing means carrying deleting data stored on the mobile device in accordance with the instruction; and a message registry, for receiving messages determined by the message analysis means not to contain an instruction, wherein said message analysis means is adapted to pass a message to the message registry if said message is determined by the message analysis means not to contain an instruction; wherein said mobile device is adapted to monitor an identification code associated with the SIM card loaded into the mobile device; and to send a reporting message to the remote device if the SIM card is changed, the reporting message including the identification code of the new SIM card; wherein the message received from the remote device and the reporting message sent to the remote device are SMS messages.

According to a tenth aspect of the invention, there is provided a mobile device containing the program of third or fourth aspects of the invention.

The program may be stored on the ROM image of the mobile device. This ensures that the program is reinstalled if the mobile device is reset.

The program may be stored on a removable memory card.

The program may be stored on an SD card installed in the mobile device.

BRIEF DESCRIPTION OF THE FIGURES

Figure 1 shows a schematic of a mobile device according to an embodiment of the present invention; Figure 2 shows the mobile device identification details stored in a remote central host system; Figure 3 shows the configuration details stored in the monitoring system registry of the mobile device of Figure 1; Figure 4 shows the start-up process executed by the monitoring system of the mobile device on initialisation; Figure 5 shows the Update SIM Details process executed by the monitoring system; and Figure 6 shows the process executed by the message monitoring system on receipt of a message.

DESCRIPTION OF THE EMBODIMENTS

Figure 1 shows a mobile device 10 according to an embodiment of the present invention.

The mobile device 10 comprises a transmitter/receiver 12 for communicating with a mobile communications network, a loud speaker 14, a microphone 16, a UPS receiver 18, a battery 20, a processor 22, a SIM (Subscriber Identity Module) card 24, a data storage area 26 and a monitoring system 30.

The mobile device 10 is monitored by a remote central host system, which may be housed in a secure location. The central host system stores identification details 60 for each mobile device 10 which it monitors. The mobile device identification details 60 (Figure 2) comprise a unique identification number 62 of the mobile device 10 and a telephone number 64 for communication with the mobile device 10 through a mobile communications network. In the preferred embodiment, the central host system stores the IMEI (International Mobile Equipment Number) of the mobile device and the telephone number of the mobile device 10. The central host system may also store other configuration details relating to the monitoring system 30 of the mobile device 10. Using the telephone number 64 of the mobile device 10, the central host system is able to send messages, e.g. SMS messages, through a wireless communication network to the mobile device 10. These messages may contain instructions to be processed by the mobile device 10, for example an instruction to delete data stored on the mobile device. The central host system is thereby able to control certain processes on the mobile device 10 remotely. The S central host system also receives messages from the mobile device 10 in response to instructions, or in response to certain events such as a change of SIM card 24 installed on the mobile device 10. The central host is thereby able to maintain and update records relating to each mobile device 10, enabling it to maintain a hnk with the mobile device 10.

The mobile device 10 is equipped with a monitoring system 30 which includes a monitoring system registry 32, a device monitoring program 34, a GPS monitoring program 36, and a message monitoring program 38. The monitoring system registry 32 stores configuration details 40, shown in Figure 3, relating to the monitoring system 30.

The device monitoring program 34 monitors events occurring in the mobile device 10 and reports these events to the central host system. Monitored events may include a change of SIM card 24 and a change in the power level of the power source 20 of the mobile device.

The GPS monitoring program 36 monitors the location of the mobile device 10 at specified intervals and reports the current location and/or changes in the location of the mobile device 10 to the central host system. The message monitoring program 38 analyses all messages received by the mobile device 10 to identify messages containing an instruction from the central host system, and extracts and processes the instruction or instructions encoded in those messages. The mobile device 10 uses a free telephone number, stored in the monitoring system registry 32, to communicate with the central host system.

The monitoring system 30 does not interfere with the normal operation of the mobile device 10 and is hidden from a user. Messages sent by the central host system to the mobile device 10 do not appear in any user-accessible message registry 28 on the mobile device 10 and are deleted from the mobile device 10 immediately after extraction and/or processing of the instruction. Likewise, messages sent by the mobile device 10 to the central host system are not stored on the mobile device 10. Thus the central host system is able to monitor the mobile device 10 discreetly, and the monitoring system 30 is unlikely to be detected and disabled. Preferably, the monitoring system 30 is incorporated as part of the ROM image installed on the mobile device 10, so that a Hard Reset of the mobile device 10 would not remove the monitoring system 30. Alternatively, the monitoring system 30 could be installed on a removable chip (e.g. a memory card or an SD card) such that the monitoring system 30 is reinstalled after a hard reset of the mobile device 10.

The monitoring system 30 can be activated and deactivated by the central host system.

This process will be described later. The monitoring system 30 may be pre-installed on mobile devices, but remain inactive (deactivated) until a later time when the mobile device identification details 60 are registered in the central host system. The monitoring system 30 may be deactivated by the central host system when it is no longer necessary to monitor the mobile device 10. An activated mobile device will respond to all instructions received from the central host system and will report monitored events to the central host system.

The monitoring system 30 of a deactivated mobile device 10 will continue to monitor messages and events, but will not respond to instructions or events by communicating with the central host system unless it is activated/re-activated.

The monitoring system 30 has two main modes of operation, "Idle" and "Monitor". If the mobile device 10 is being monitored by the central host system, the monitoring system will be set to "Monitor" mode, and will report to the central host system in response to all events and instructions. In "Monitor" mode, the GPS monitoring program 36 is active. If the mobile device 10 is not being monitored by the central host system, the monitoring system 30 will be set to [dle" mode. In "Idle" mode, the monitoring system 30 continues to monitor device events, but certain events, including changes in power level, are not reported to the central host system. In "Idle" mode, the GPS monitoring program 36 is inactive.

Start up The monitoring system 30 is initialised each time the mobile device 10 is powered on. On initialisation, the start-up process illustrated in Figure 4 is executed. This includes a step of reading current configuration details 40 (Figure 3) stored in the monitoring system registry 32 on the mobile device 10, including the last SIM card details 44, the current activation status 50 and the cunent device monitoring status 59. If the current device monitoring status 59 indicates that the mobile device 10 is being monitored by the central host system, the monitoring system sets itself to "Monitor" mode. Otherwise, the monitoring system is set to "Idle" mode. Next, the device monitoring program 34, the GIPS monitoring program 36 and the message monitoring program 38 are each initialised, with S reference to the current configuration details 40 stored in the monitoring system registry 32. Finally, the monitoring system 30 checks the details of the SIM card 24 currently installed in the mobile device 10, by executing the Update SIM Details process shown in Figure 5. The monitoring system 30 reads the SIM card details stored on the currently installed SIM card 24 and compares these with the previous SIM card details stored in the monitoring system registry 32. In particular, the monitoring system 30 reads and compares the telephone number stored on the currently installed SIM card 24 and compares this number with the previous telephone number 64 stored in the monitoring system registry 32. If the SIM card details match, no action is taken. However, if the SIM card details are different, and provided that the monitoring system 30 is activated, the monitoring system 30 encodes the mobile device identification details 60 (including the new telephone number 64 corresponding to the currently installed SIM card 24, and the unique device identification number 62 of the mobile device 10) in an SMS message, which it sends to the central host system. The central host system updates its record for the mobile device by storing the new SIM card details, including at least the new telephone number 64, against the unique device identification number 62. The monitoring system 30 on the mobile device 10 updates the local configuration details 40, by storing the new SIM card details, including at least the new telephone number of the new SIM card 24, in the monitoring system registry 32.

Fvent monitoring The device monitoring program 34 monitors events occurring in the mobile device 1 0, including a change of SIM card 24 and a change in the power level of the mobile device 10, and reports these events to the central host system. However, if the monitoring system is deactivated, no events are reported to the central host system.

While the mobile device 10 is powered on, if the monitoring system 30 detects that the currently installed SIM card 24 has changed, it executes the Update SIM Details process illustrated in Figure 5 and described above. The monitoring system 30 encodes the device identifier details 60, including the new telephone number 64 corresponding to the new SIM card 24 and the unique device identification number 62 of the mobile device 10, in an SMS message, which it sends to the central host system. Provided that the monitoring system 30 is activated, the mobile device 10 will report a change of S1M card to the central host system regardless of whether the monitoring mode is set to "Monitor" or "Idle". The central host system updates its record for the mobile device 10 and the monitoring system on the mobile device 10 updates the local configuration details 40, as described above.

Usually, it is necessary to remove the battery 20 of a mobile device 10 in order to change the SIM card 24. In that case, the SIM card change wilt be detected during the start up process executed when the mobile device is powered on. However, in some mobile devices, the SIM card 24 can be changed without removing the battery 20. For this type of mobile device, changing the SIM card 24 without removing the battery 20 or powering off the mobile device 10 would result in a change of SIM card event being detected by the device monitoring program 34.

If the power level of the battery 20 of the mobile device 10 falls below a predetermined threshold, a change in power level event will be detected by the device monitoring program 34. This may correspond, for example, to a change in the power indicator 21 of the battery 24. If the monitoring system 30 is in "Monitor" mode, the monitoring program will send an SMS message comprising a power level warning to the central host system to alert the central host system of impending loss in power. If the monitoring system 30 is in "Idle" mode, no power level warning is sent to the centra] host system.

GPS monitoring The UPS monitoring program 36 monitors the location of the mobile device 10 at specified intervals and reports the current location and/or changes in the location of the mobile device 10 to the central host system. The UPS monitoring Thnction can be turned on and off by the central host system remotely, as will be described below. When the monitoring system 30 is set to "Monitor" mode, the UPS monitoring program 36 triggers a UPS event at predetermined intervals, the intervals being determined according to a UPS interval setting 56 stored in the monitoring system registry 32 of the mobile device 10. Each time a UPS event is triggered, the mobile device 10 obtains current UPS data using its UPS receiver, and the monitoring program 30 sends the UPS data to the central host system in an SMS message.

Message monitoring The message monitoring program 38 of the monitoring system 30 includes a message analysis program and an instruction processing program. The message analysis program receives all messages sent by a remote device and destined for the mobile device 10. A "message" may be nnderstood to be any data packet sent between any remote device and the mobile device 10. In the preferred embodiment, messages are sent and received as SMS messages, but the method could be implemented using email. Messages are generally routed to a particular mobile device 10 by specifying the telephone number 64 associated with the mobile device 10.

Conventionally, when a mobile device 10 receives a message, the message is transferred to a message registry 28 of the mobile device 10. A user of the mobile device 10 is able to access the message registry 28 to view the messages received. However, in the present invention, not all messages are routed to the message registry 28. Messages are intercepted by the message monitoring program 38, and are first analysed by the message analysis program to determine whether a message contains an instruction from the central host system. A message may be identified as containing an instruction by, for example, its format, or by some other identifier, such as a pre-defined set of characters contained in message. The message analysis program may analyse the body of the message to determine whether it contains an instruction. Alternatively, the message analysis program may analyse the header of the message to determine whether the message source, or some other identifier matches an identifier stored in the monitoring system registry 30. If a message is identified as containing an instruction, the message analysis program may perform an authentication process to verify that the message has been sent by the central host system or some other authorised source.

If the message analysis program determines that a message contains an instruction from the central host system, the message is not transmitted to the message registry 28. Instead, the instruction is extracted from the message and the instruction is passed to the instruction processing program for processing. The original message is deleted. The user of the mobile device 10 therefore remains unaware that the message has been received.

Examples of instructions are:

ACTIVATE

DEACTIVATE

MONITOR_ON

MONITOR_OFF

CONFIGURE

RETRIEVE ID

SEND_LOCATION

DESTROY DATA

IDENTIFY.

This list of instructions is not exhaustive, and other instructions may be contemplated.

Although each message may contain more than one instruction, it is preferable that each message contains no more than one instruction.

Figure 6 shows the process executed by the message monitoring program on receipt of a message.

The ACTIVATE and DEACTIVATE instructions are used to change the status 50 of the mobile device between "Activated" and "Deactivated". The status 50 of the mobile device is stored as a parameter in the monitoring system registry 32. An activated mobile device will respond to all instructions received from the central host system and will report monitored events to the central host system. A mobile device which is not activated will not respond to any instruction other than ACTIVATE The MONITOR_ON and MONITOR OFF instructions are used to set the monitoring system 30 to "Monitor" mode or "Idle" mode. The "Monitor" mode indicates that the mobile device 10 is currently being monitored by the central host system and activates the GPS monitoring flmction. On receiving a MONITOR_ON instruction, the instruction processing program switches on the UPS receiver 18 of the mobile device 10 and activates the UPS monitoring function. The UPS monitoring program triggers a UPS event at times determined according to a UPS interval setting 56 stored with the configuration details 40 in the monitoring system registiy 32. Each time that a UPS event is detected, the mobile device 10 obtains GPS location details using the UPS receiver 18 and sends these details in an SMS message to the central host system. On receiving a MONITOR_OFF instruction, the instruction processing program switches off the GPS receiver of the mobile device and deactivates the GPS monitoring function. When set to "Monitor" mode, the mobile device also reports power level events to the central host system, to alert the central host system to any impending loss of power while the device 10 is being monitored. The current device monitoring status 59 is stored in the monitoring system registry 32 and is used on start up to set the monitoring system mode to the previous mode setting used before the mobile device 10 was powered down.

The CONFIUURE instruction is used to update the configuration details 40 stored in the monitoring system registry 30 of the mobile device 10, for example the telephone number used to send SMS messages to the central host system, or the UPS interval setting. On receipt of a CONFIGURE instruction, the instruction processing program encodes the configuration details extracted from the SMS message, and updates the configuration details 40 stored in the mobile device 10.

The RETR1E VE ID instruction is used to add a new mobile device 10 to the central host system. On receipt of the RETRIE yE ID instruction, the instruction processing program extracts the unique device identification number from the mobile device 10 and reads the telephone number stored on the SIM card 24 installed in the mobile device 10.

(Alternatively, these numbers may be obtained from the configuration details 40 stored in the monitoring system registry 30.) The instruction processing program then encodes these numbers in an SMS message which is sent to the central host system.

On receiving a SEND_LOCATION instruction, the instruction processing program switches on the UPS receiver 18 of the mobile device 10, retrieves UPS location details corresponding to the current location of the mobile device, and sends these details in an SMS message to the central host system, and then switches off the UPS receiver 18.

The DESTROY_DATA instruction allows the data stored on the mobile device 10 to be destroyed by sending an SMS message from the central host system to the mobile device 10, for example if the mobile device 10 is lost or stolen. On receipt of a DESTROY_DATA instruction, the instruction processing program permanently deletes data stored on the mobile device. Preferably, the instruction processing program deletes messages (SMS messages) and/or emails stored on the mobile device 10. The instruction processing program may also delete electronic documents (e.g. spreadsheets, images, pdf files) stored on the mobile device 10 and user-defined data (e.g. data relating to the local email account, passwords). Preferably, the monitoring system 30 is configured to send one or more SMS messages confirming deletion of local data. Optionally, the monitoring system 30 may be configured to delete specific data in response to the instruction, or the instruction may contain further information specifying data to be deleted. The data to be deleted may include data stored on a removable memory card.

The IDENTIFY instruction can be used to locate the mobile device 10. On receipt of an IDENTIFY instruction, the instruction processing program causes the loud speaker 14 of the mobile device 10 to emit an alarm tone. If necessary, the instruction processing program deactivates the mute function of the mobile device 10 and/or sets the volume level of the loud speaker 14 to maximum before the alarm sound is emitted.

After processing an instruction, the monitoring system 30 sends a confinnation message to the central host system with the details of the instruction processed. In some embodiments, if a MONITOR_ON instruction is received from the central host system, but the monitoring system 30 is deactivated, the monitoring system 30 sends a message to the central host system to inform it of the device status 50.

All messages sent by the monitoring system 30 from the mobile device 10 to the central host system include the unique device identification number 62 of the mobile device 10 and may also include a time stamp.

The advantages of the above-described system can be appreciated by considering the example of theft of the mobile device 10. On realising that the mobile device 10 has been stolen, the user can use the central host system to send a message to the mobile device containing an instruction to delete data stored in the mobile device. Registered users (owners of activated devices) may have access to specific areas of the central host system for this purpose. Alternatively, if the user does not realise that the mobile device 10 has been stolen, but a thief changes the SIM card of the device, then a change of SIM card event will be detected and reported to the central host system, enabling the user to be notified of the theft. The new SIM card details are automatically reported to the central host system, which is therefore stilt able to send instruction messages to the mobile device 10. The central host system may be configured to send a DELETE instruction automatically on receipt of message reporting a particular event. If a user is unsure whether a mobile device 10 has been Lost or stolen, he can use the SEND LOCATION and/or IDENTTFY instructions to determine the location of the mobile device 10.

Although the method has been described with particular reference to SMS messages, other methods of communication between the mobile device 10 and the central host system may be contemplated. It is advantageous to use a standard messaging system which is already installed on the mobile device, as this reduces the processing power and data storage capacity required by the monitoring system 30.

It will be appreciated by persons skilled in the art that the above embodiments have been described by way of example only and not in any limitative sense, and that various alterations and modifications are possible without departure from the scope of the invention as defined by the appended claims. In particular the mobile device, method and program may be adapted to monitor instructions and events other than those described above. For example, an instruction may be used to retrieve data from the mobile device 10 by instructing the device 10 to send data to the central host system. Other instructions or events may be contemplated, including specific combinations or sequences of the above-described instructions and events.

Claims

CLAIMS1. A method to be implemented on a mobile device, the method comprising the steps of: receiving a message from a remote device; analysing the message to determine whether said message contains an instruction; and processing the message, the step of processing the message including, if the message contains an instruction, extracting the instruction from the message and passing the instruction to an instruction processing means of said mobile device, and, if the message does not contain an instruction, passing said message to a message register means of said mobile device.
2. The method of claim 1, further comprising the step of, if the message contains an instruction, verifying the source of the message, wherein an instruction contained in a message is passed to the instruction processing means for processing if and only if the source verification is successful.
3. The method of claim 1 or 2, wherein, if the message contains an instruction, the message is not passed to the message register means of the mobile device.
4. The method of any one of claims ito 3, wherein, if the message contains an instruction, the message is deleted after extraction of the instruction.
5. The method of any one of claims 1 to 4, comprising the further step of said instruction processing means receiving and processing the instruction.
6. The method of claim 5, wherein if the instruction is to destroy data stored on the mobile device, the mobile device deletes data stored on the mobile device.
7. The method of claim 6, wherein the data deleted by the mobile device includes at least one of: messages stored on the mobile device; emails stored on the mobile device; user-defined data stored on the mobile device; electronic documents stored on the mobile device.
8. The method of any one of claims S to 7, wherein, in response to an instruction containing configuration settings, the mobile device updates one or more configuration settings stored on the mobile device, in accordance with the instruction.
9. The method of any one of claims S to 8, wherein, in response to an instruction containing a function status, the remote device enables or disables a ftmction of the mobile device in accordance with the instruction.
10. The method of any one of claims 5 to 9, wherein the mobile device includes a GPS receiver, and wherein, in response to an instruction requesting location data, the remote device switches on the GPS receiver and receives GPS data relating to the location of the mobile device.
11. The method of any one of claims 5 to 10, wherein the mobile device includes a speaker and, if the instruction is to identify the mobile device, then the mobile device causes the loud' speaker to emit an alarm.
12. The method of claim 11, wherein the mobile device sets the loud speaker volume to maximum before emitting an alarm.
13. The method of any one of claims 5 to 12, further comprising the step of sending a message to the remote device in response to the instruction.
14. The method of claim 13, wherein, in response to an instruction requesting information, the message sent to the remote device contains information requested by the remote device.
15. The method of claim 14, wherein the message sent to the remote device contains at least one of: data relating to the location of the device; configuration data stored on the mobile device; data stored on the SIM card of the mobile device.
16. The method of claim 15, wherein the message sent to the remote device confinns that the instruction has been processed.
17. The method of claim 15, wherein the message sent to the remote device is not stored on the mobile device.
18. The method of any one of claims 5 to 17, wherein the step of processing of the instruction overrides any other program running on the mobile device.
19. The method of any one of the preceding claims, further comprising the steps of: monitoring at least one property of the mobile device; and sending a reporting message to the remote device when the value of said at least one property of the mobile device is within a specified range.
20. The method of claim 19, wherein the step of sending a message to a remote device includes encoding the value of said at least one property of the mobile device in said reporting message and sending said reporting message to the remote device.
21. The method of claim 19 or claim 20, wherein a reporting message is sent to the remote device only if a monitor status of the mobile device is active.
22. The method of any one of claims 19 to 21, wherein the reporting message sent to the remote device is not stored on the mobile device.
23. The method of any one of claims 19 to 22, wherein the at least one the property S monitored includes at least one of: an identification code associated with the SIM card loaded into the mobile device; the power level of the mobile device; and the location of the mobile device.
24. The method of any one of claims 19 to 23, wherein the at least one property is monitored continuously.
25. The method of any one of claims 19 to 24, wherein the at least one property is monitored at specified intervals.
26. The method of any one of claims 19 to 24, wherein the at least one property is monitored each time that the mobile device is powered on.
27. A method to be implemented by a mobile device, for enabling remote monitoring of the mobile device by a remote device, the method comprising the steps of: monitoring at least one property of the mobile device; and sending a message to a remote device when the value of at least one property of the mobile device is within a specified range.
22. The method of claim 27, wherein the step of sending a message to a remote device includes encoding the value of said at least one property of the mobile device in said message and sending said message to the remote device.
29. The method of claim 27 or claim 28, wherein a message is sent to the remote device only if a monitor status of the mobile device is active.
30. The method of any one of claims 27 to 29, wherein the message sent to the remote device is not stored on the mobile device.
31. The method of any one of claims 27 to 30, wherein the at least one the property monitored includes at least one of: an identification code associated with the SIM card loaded into the mobile device; the power level of the mobile device; and the location of the mobile device.
32. The method of any one of claims 27 to 31, wherein the at least one property is monitored continuously.
33. The method of any one of claims 27 to 32, wherein the at least one property is monitored at specified intervals.
34. The method of any one of claims 27 to 32, wherein the at least one property is monitored each time the mobile device is powered on.
35. The method of any one of claims I to 34, wherein a message is an SMS message.
36. A method to be implemented on a mobije device adapted to communicate with a remote device through a mobile communications link, the method comprising the steps of: receiving a message from a remote device; analysing the message to determine whether said message contains an instruction; processing the message, the step of processing the message including, if the message does not contain an instruction, passing said message to a message register means of said mobile device; and, if the message contains an instruction, extracting the instruction from the message and passing the instruction to an instruction processing means of said mobile device, the instruction processing means carrying out the step of deleting data stored on the mobile device; monitoring an identification code associated with the SIM card loaded into the mobile device; and sending a reporting message to the remote device if the SIM card is changed, the reporting message including the identification code of the new SIM card; wherein the message received from the remote device and the reporting message sent to the remote device are SMS messages.
37. A program comprising computer program code adapted, when said program is loaded onto a mobile device, to make the mobile device execute the steps of receiving a message from a remote device; analysing the message to determine whether said message contains an instruction; and processing the message, the step of processing the message including, if the message contains an instruction, extracting the instruction from the message and passing the instruction to an instruction processing means of said mobile device, and, if the message does not contain an instruction, passing said message to a message register means of said mobile device.
38. The program of claim 37, further adapted to make the mobile device execute the step of, if the message contains an instruction, verifying the source of the message, wherein an instruction contained in a message is passed to the instruction processing means for processing if and only if the source verification is successthl.
39. The program of claim 37 or 38, wherein, if the message contains an instruction, the message is not passed to the message register means of the mobile device.
40. The program of any one of claims 37 to 39, wherein, if the message contains an instruction, the message is deleted after extraction of the instruction.
41. The program of any one of claims 37 to 40, further adapted to make the mobile device execute the step of said instruction processing means receiving and processing the instruction.
42. The program of claim 41, wherein if the instruction is to destroy data stored on the mobile device, the mobile device deletes data stored on the mobile device.
43. The program of claim 42, wherein the data deleted by the mobile device includes at least one of: messages stored on the mobile device; emails stored on the mobile device; user-defined data stored on the mobile device; and electronic documents stored on the mobile device.
44. The program of any one of claims 41 to 43, wherein, in response to an instruction containing configuration settings, the mobile device updates one or more configuration settings stored on the mobile device, in accordance with the instruction.
45. The program of any one of claims 41 to 44, wherein, in response to an instruction containing a function status, the remote device enables or disables a function of the mobile device in accordance with the instruction.
46. The program of any one of claims 41 to 45, wherein the mobile device includes a UPS receiver, and wherein, in response to an instruction requesting location data, the remote device switches on the UPS receiver and receives UPS data relating to the location of the mobile device.
47. The program of any one of claims 41 to 46, wherein the mobile device includes a speaker and, if the instruction is to identify the mobile device, then the mobile device causes the loud speaker to emit an alarm.
48. The program of claim 47, wherein the mobile device sets the loud speaker volume to maximum before emitting an alarm.
49. The program of any one of claims 5 to 48, further adapted to make the mobile device execute the step of sending a message to the remote device in response to the instruction.
50. The program of claim 49, wherein, in response to an instruction requesting information, the message sent to the remote device contains information requested by the remote device.
51. The program of claim SO, wherein the message sent to the remote device contains atleastoneof: data relating to the location of the device; configuration data stored on the mobile device;and data stored on the SIM card of the mobile device.
52. The program of claim 51, wherein the message sent to the remote device confirms that the instruction has been processed.
53. The program of claim 51, wherein the message sent to the remote device is not stored on the mobile device.
54. The program of any one of claims 41 to 53, wherein the step of processing of the instruction overrides any other program running on the mobile device.
55. The program of any one of the preceding claims, further adapted to make the mobile device execute the steps of: monitoring at least one property of the mobile device; and sending a reporting message to the remote device when the value of said at least one property of the mobile device is within a specified range.
56. The program of claim 55, wherein the step of sending a message to a remote device includes encoding the value of said at least one property of the mobile device in said reporting message and sending said reporting message to the remote device.-3 8-.
57. The program of claim 55 or claim 56, wherein a reporting message is sent to the remote device oniy if a monitor status of the mobile device is active.
58. The program of any one of claims 55 to 57, wherein the reporting message sent to the remote device is not stored on the mobile device.
59. The program of any one of claims 55 to 58, wherein the at least one the property monitored includes at least one of: an identification code associated with the SIM card loaded into the mobile device; the power level of the mobile device; and the location of the mobile device.
60. The program of any one of claims 55 to 59, wherein the at least one property is monitored continuously.
61. The program of any one of claims 55 to 60, wherein the at least one property is monitored at specified intervals.
62. The program of any one of claims 55 to 60, wherein the at least one property is monitored each time that the mobile device is powered on.
63. A program comprising computer program code adapted, when said program is loaded onto a mobile device, to make the mobile device execute the steps of: monitoring at least one property of the mobile device; and sending a message to a remote device when the value of at least one property of the mobile device is within a specified range.
64. The program of claim 63, wherein the step of sending a message to a remote device includes encoding the value of said at least one property of the mobile device in said message and sending said message to the remote device.
65. The program of claim 63 or claim 64, wherein a message is sent to the remote device only if a monitor status of the mobile device is active.
66. The program of any one of claims 63 to 65, wherein the message sent to the remote device is not stored on the mobile device.
67. The program of any one of claims 63 to 66, wherein the at least one the property monitored includes at least one of: an identification code associated with the SIM card loaded into the mobile device; the power level of the mobile device; and the location of the mobile device.
68. The program of any one of claims 63 to 67, wherein the at least one property is monitored continuously.
69. The program of any one of claims 63 to 68, wherein the at least one property is monitored at specified intervals.
70. The program of any one of claims 27 to 68, wherein the at least one property is monitored each time the mobile device is powered on.
71. The program of any one of claims 37 to 70, wherein a message is an SMS message,
72. A program comprising computer program code adapted, when said program is loaded onto a mobile device, to make the mobile device execute the steps of receiving a message from a remote device; analysing the message to determine whether said message contains an instruction; processing the message, the step of processing the message including, if the message does not contain an instruction, passing said message to a message register means of said mobile device; and, if the message contains an instruction, extracting the instruction from the message and passing the instruction to an instruction processing means of said mobile device, the instruction processing means carrying out the step of deleting data stored on the mobile device; monitoring an identification code associated with the SIM card loaded into the mobile device; and sending a reporting message to the remote device if the SIM card is changed, the reporting message including the identification code of the new SIM card; wherein the message received from the remote device and the reporting message sent to the remote device are SMS messages.
73. A mobile device adapted to communicate with a remote system by sending and receiving messages through a mobile communications network) the mobile device comprising: a message analysis means, adapted to determine whether a message received from a remote device contains an instruction, and to extract an instruction from a message determined to contain an instruction; a processing means, adapted to receive and process instructions extracted by the message analysis means; and a message registry, for receiving messages determined by the message analysis means not to contain an instruction, wherein said message analysis means is adapted to pass a message to the message registry if said message is determined by the message analysis means not to contain an instruction.
74. The mobile device of claim 73, wherein the message analysis means is adapted to verify the source of a message received from a remote device, and to pass an instruction contained in the message to the instruction processing means if and only if the source verification is successful.
75. The mobile device of claim 73 or claim 74, wherein the message analysis means is adapted to pass a message to the message registry if and only if the message has been determined not to contain an instruction.
76. The mobile device of any one of claims 73 to 75, wherein the message analysis means is adapted to delete a message determined to contain an instruction, after extraction of the instruction.
77. The mobile device of any one of the preceding claims, wherein the instruction processing means is adapted to delete data stored on the mobile device if an instruction to destroy data is received from a remote device.
78. The mobile device of claim 77, wherein the data deleted by the mobile device includes at least one of: messages stored on the mobile device; emails stored on the mobile device; user-defined data stored on the mobile device; and electronic documents stored on the mobile device.
79. The mobile device of any one of the preceding claims, wherein the instruction processing means is adapted, in response to an instruction containing configuration settings, to update one or more configuration settings stored on the mobile device, in accordance with the instruction.
80. The mobile device of any one of the preceding claims, wherein the instruction processing means is adapted, in response to an instruction containing a ftmnction status, to enable or disable a function of the mobile device in accordance with the instruction.
81. The mobile device of any one of the preceding claims, further comprising a UPS receiver, the mobile device being adapted, in response to an instruction requesting location data, to switch on the UPS receiver and receive UPS data relating to the location of the mobile device.
82. The mobile device of any one of the preceding claims, further comprising a loud speaker, the mobile device being adapted, if the instruction is to identify the mobile device, to cause the loud speaker to emit an alarm.
83. The mobile device of claim 82, wherein the mobile device is adapted to set the loud speaker volume to maximum before emitting an alarm.
84. The mobile device of any one of the preceding claims, wherein the instruction processing means is adapted to send a message to the remote device in response to an instruction.The mobile device of claim 84, wherein the message sent to the remote device contains information requested by the remote device.86. The mobile device of claim 85, wherein the message sent to the remote device contains at least one of data relating to the location of the device; configuration data stored on the mobile device; and data stored on the SIM card of the mobile device.87. The mobile device of claim 84, wherein the instruction processing means is adapted to send a confirmation message to the remote device after processing of the instruction.88. The mobile device of claim 84, wherein the message sent to the remote device is not stored on the mobile device.89. The mobile device of any one of the preceding claims, wherein the instruction processing means is adapted to oven-ide any other program running on the mobile device.90. The mobile device of any one of the preceding claims, farther adapted to monitor at least one property of the mobile device and to send a reporting message to the remote device when the value of said at least one property of the mobile device is within a specified range.91. The mobile device of claim 90, farther adapted to send a reporting message encoding the value of said at least one property of the mobile device to the remote device.92. The mobile device of claim 90 or claim 91, adapted to send a reporting message to the remote device only if a monitor status of the mobile device is active.93. The mobile device of any one of claims 90 to 92, wherein the reporting message sent to the remote device is not stored on the mobile device.94. The mobile device of any one of claims 90 to 93, wherein the at least one the property monitored includes at least one of: an identification code associated with the SIM card loaded into the mobile device; the power level of the mobile device; and the location of the mobile device.95. The mobile device of any one of claims 90 to 94, wherein the mobile device is adapted to monitor said at least one property continuously.96. The mobile device of any one of claims 90 to 95, wherein the mobile device is adapted to monitor said at least one property at specified intervals.97. The mobile device of any one of claims 90 to 95, wherein the mobile device is adapted to monitor said at least one property each time the mobile device is powered on.98. A mobile device adapted to communicate with a remote system by sending messages through a mobile communications network, the mobile device being adapted to monitor at least one property of the mobile device, and to send a message to the remote device when the value of said at least one property of the mobile device is within a specified range.99. The mobile device of claim 98, further adapted to send a message encoding the value of said at least one property of the mobile device to the remote device.100. The mobile device of claim 98 or claim 99, adapted to send a message to the remote device only if a monitor status of the mobile device is active.101. The mobile device of any one of claims 98 to 100, wherein the message sent to the remote device is not stored on the mobile device.102. The mobile device of any one of claims 98 to 101, wherein the at least one the property monitored includes at least one of an identification code associated with the SIM card loaded into the mobile device; the power level of the mobile device; and the location of the device.103. The mobile device of any one of claims 98 to 102, wherein the mobile device is adapted to monitor said at least one property continuously.104. The mobile device of any one of claims 98 to 103, wherein the mobile device is adapted to monitor said at least one property at specified intervals.105. The mobile device of any one of claims 98 to 103, wherein the mobile device is adapted to monitor said at least one property each time the mobile device is powered on.106. The mobile device of any one of claims 73 to 105, wherein the message is an SMS message.107. A mobile device adapted to communicate with a remote system by sending and receiving messages through a mobile communications network, the mobile device comprising: a message analysis means, adapted to determine whether a message received from a remote device contains an instruction, and to extract an instruction from a message determined to contain an instruction; an instruction processing means, adapted to receive and process instructions extracted by the message analysis means; the instruction processing means carrying deleting data stored on the mobile device in accordance with the instruction; and a message registry, for receiving messages determined by the message analysis means not to contain an instruction, wherein said message analysis means is adapted to pass a message to the message registry if said message is determined by the message analysis means not to contain an instruction; wherein said mobile device is adapted to monitor an identification code associated with the SIM card loaded into the mobile device; and to send a reporting message to the renlote device if the SIM card is changed, the reporting message including the identification code of the new S1M card; wherein the message received from the remote device and the reporting message sent to the remote device are SMS messages.108. A mobile device containing the program of any one of claims 37 to 72.109. The mobile device of claim 108, wherein the program is stored on the RUM image of the mobile device.110. The mobile device of claim 109, wherein the program is stored on a removable memory card.111. The mobile device of claim 109, wherein the program is stored on an SD card installed in the mobile device.112. A method to be implemented on a mobile device, substantially as hereinbefore described with reference to the accompanying drawings.113. A program comprising computer program code, substantially as hereinbefore described with reference to the accompanying drawings.114. A mobile device adapted to communicate with a remote system by sending and receiving messages through a mobile communications network, substantially as hereinbefore described with reference to the accompanying drawings.