WO2007069176A2

WO2007069176A2 - Method for the detection of a use of a camera unit in a mobile device

Info

Publication number: WO2007069176A2
Application number: PCT/IB2006/054730
Authority: WO
Inventors: Rajendra S. Sisodia
Original assignee: Koninklijke Philips Electronics N.V.
Priority date: 2005-12-16
Filing date: 2006-12-11
Publication date: 2007-06-21
Also published as: WO2007069176A3

Abstract

A method for the detection of a use of a camera unit in a mobile device is provided. A signal for initiating the detection mode for detecting the use of a camera unit is wirelessly received. A hashing function on operation codes performed by the camera unit and/or the hashing function of memory modules associated with the function of the camera unit is performed at at least a first point of time to determine a first hash value. Thereafter, a hash function is performed on operation codes performed by the camera unit and/or a hashing function is performed on the memory modules associated with the function of the camera unit at at least a second point of time to determine a second hash value. The first and second hash values are transmitted. The received first and second hash values are compared and a warning signal is initiated if the first and second hash values do not match.

Description

Method for the detection of a use of a camera unit in a mobile device

FIELD OF THE INVENTION

The invention relates to a method for the detection of a use of a camera unit in a mobile terminal, a mobile device with a camera unit and a security monitoring system.

BACKGROUND OF THE INVENTION

With the development of mobile devices or mobile terminals which may comprise detachable memory modules or external memory devices, the possibilities to transfer data easily have significantly increased. External memory devices may be constituted by a USB memory stick, memory card or the like. Additionally, the provision of camera units in mobile devices or mobile terminals has resulted in an increased danger of pictures or videos being taken in restricted or private areas without anybody noticing. Such mobile devices with camera units may be misused for espionage or may be misused for taking pictures in a private environment. However, as a lot of current mobile phones also have camera units, it is difficult to control the use of the camera units of such mobile telephones. On the other hand, it is not acceptable to users of mobile phones with camera units if the mobile phones have to be left aside when the users enter a restricted or private area, as these mobile devices are also a means of communication for the users.

US 2005/0064856 discloses a method for managing the operation of a camera in a mobile communications unit. Depending on the location of the mobile communications unit, a signal is sent to the mobile communications unit, which signal causes at least one function of the camera unit to be disabled. These camera functions may include the ability to take a picture, to select a picture resolution, the ability to record audio, the ability to record video or provide a flash function. The location of the mobile communications unit may be determined by a global positioning system, a triangulation process or a wireless transmission. The signal to limit the functions of the camera of the mobile communications unit may also be sent in accordance with a Bluetooth protocol.

It can therefore be expected that such a functionality will be implemented in almost all mobile phones with a camera unit, so that after receiving a specific signal, the camera functionality of the mobile phone is restricted for a specified amount of time. SUMMARY OF THE INVENTION

It is an object of the invention to provide a method for the detection of a use of a camera unit in a mobile terminal, which can be implemented more easily from the environment of the mobile device.

This object is solved by a method for the detection of a use of a camera unit in a mobile terminal according to claim 1 , a mobile device according to claim 5 and a security monitoring system according to claim 9.

Therefore, a method for the detection of a use of a camera unit in a mobile device is provided. A signal for initiating the detection mode for detecting the use of a camera unit is received in wireless fashion. A hashing function is performed on operation codes performed by the camera unit and/or on memory modules associated with the function of the camera unit at a first point of time to determine a first hash value. Thereafter, a hash function is performed on operation codes performed by the camera unit and/or on the memory modules associated with the function of the camera unit at a second point of time to determine a second hash value. The first and second hash values are transmitted. The received first and second hash values are compared and a warning signal is initiated if the first and second hash values do not match.

Accordingly, any use of a camera unit in a mobile device can be detected and any security personnel may be notified.

According to one aspect of the invention the first and/or second hash values are determined at regular intervals if the signal for initiating the detection mode is received. Hence, if the detection mode is activated, the detection of the use of the camera unit can be performed on a regular basis. According to another aspect of the invention the determined first and second hash values are transmitted at regular intervals if the signal for initiating the detection mode is received. Hence, if the detection mode is activated, the security personnel will be updated at regular intervals on the use of a camera unit.

According to a further aspect of the invention the position of the mobile device is determined. Furthermore, there is determined whether the position of the mobile device is in a specified area. The first and second hash values are not compared if the determined position of the mobile device is outside the specified area. Therefore, it can be prevented that the use of a camera unit is detected if the position of the mobile device is outside a restricted area. The invention also relates to a mobile device comprising a camera unit for taking pictures or videos, and a wireless receiver unit for receiving a signal to initiate a detection mode for detecting the use of the camera unit. The device furthermore comprises at least one memory module for storing the output data of the camera unit, and a hash computing unit for computing a hash value of the memory modules that are used to store the output data of the camera unit and for computing a hash value on the operation codes of the camera unit. A transmitter unit wirelessly transmits the hash value as computed by the hash computing unit.

The invention also relates to a security monitoring system for monitoring the use of a camera unit in a mobile device. The security monitoring system comprises a transmitter unit for transmitting a signal to initiate the detection of the use of the camera unit. The transmitter unit is also adapted to receive hash values transmitted by a mobile device. The system furthermore comprises a hash database for storing hash values of operational codes of a camera and/or for storing hash values of memory modules associated with the function of the camera unit. A hash comparator unit compares the received hash values with hash values stored in the hash database in order to determine whether the hash values have changed. A warning signal is initiated if the hash values have changed.

The invention relates to a method in which a signal is transmitted to restrict the use of a camera unit. A hash function is computed for those memory blocks associated with the function of the camera unit and is transmitted to the device that is sending the specific signal to disable the function of the camera unit. The memory module associated with the camera unit is hashed, i.e. an automatic signature of the memory module is produced and these hashed values are transmitted. The transmitted hashed values are compared to infer whether the camera unit has been used. In other words, a specific signal for disabling the camera unit is received by the mobile device. A hash function of the memory block associated with the camera unit is produced. The hash value is transmitted to a receiver of the transmitter device that transmits the signal for disabling the camera unit. If the user leaves the restricted area, a new hash value of the memory blocks associated with the camera unit is determined and transmitted. In the transmitter device the hash value of the memory modules associated with the camera unit of the mobile device which was determined when the mobile device entered the restricted area is compared to the hash value of the memory blocks associated with the camera unit when the mobile terminal leaves the restricted area or after a predetermined period of time has elapsed. By comparing these two hash values, there may be inferred whether the user has used the camera unit of his mobile device.

These and other aspects of the invention are defined in the dependent claims.

BRIEF DESCRIPTION OF THE DRAWINGS

The embodiments and advantages of the present invention will now be described in more detail with reference to the figures.

Fig.l shows a block diagram of a mobile device according to the first embodiment,

Fig.2 shows a block diagram of a special signal controller device,

Fig.3 shows a flow chart of the method for the detection of the use of a camera unit in a mobile device according to a first embodiment, and

Fig.4 shows a block diagram of those parts of the mobile phone which are used to determine the hash function.

DESCRIPTION OF PREFERRED EMBODIMENTS

Fig.l shows a block diagram of the basic architecture of a mobile device according to a first embodiment. The mobile device comprises a receiver module 10 for wirelessly receiving a special signal 100. The mobile device furthermore comprises a controller 20, memory modules 30, a camera/video unit 40, a hash computing unit 60 and a hash transmitter 70. The receiver module 10 controls the camera/video unit 40 via the controller 20. If a special signal or detecting mode signal SGlOO is received, the operation of the camera/video unit 40 may be temporarily shut down. Alternatively or additionally, when the SG signal or detection mode is received, the memory modules 30 which are associated with the operation of the camera/video unit are switched to a special operating mode, i.e. the detection mode. In this special operating mode, the hash computing unit 60 computes a hash value of the memory modules and forwards this hash value to the hash transmitter 70 which transmits this value to a receiver of the transmitter of the special signal 100. For example, if a user of the mobile device which may be used as a mobile phone uses the camera unit 40 for example to take a picture, the output data of the camera/video unit 40 will be stored in the memory modules 30 that are associated with the function of the camera/video unit. The hash computing unit 60 computes a hash value of the memory modules that are associated with the function of the camera/video unit and may also compute a hash value of the operation codes which are performed by the camera unit 40 on the memory modules. If a special signal or detection mode signal 100 is received by the mobile phone via its receiver module 10, the operation of the hash computing unit 60 is initiated and a hash value of the memory modules and the operation codes is determined. If a further special signal 100 is received, the hash computing unit 60 computes a new hash value of the memory modules 30 as well as of the operation codes. Alternatively or additionally, this may also be performed after predetermined time intervals and the computed hash value may be stored in a special part of the memory modules. The hash values of the memory modules as well as the operation codes may be stored for a predetermined period of time or may be replaced by new hash values. Furthermore, the stored hash values may be transmitted at predetermined or regular time intervals or upon a reception at the signal 100. The receiver module 10 and the hash transmitter 70 may be used as a single receiver/transmitter unit.

Fig.2 shows a block diagram of a controller device or a security monitoring device according to the first embodiment. The controller device comprises a hash comparator unit 110, a controller unit 120, a hash database 130, a transmitter unit 140 and a mobile detector unit 160. The mobile detector unit 160 serves to detect any mobile devices or mobile terminals within its range. Alternatively or additionally, such a mobile detector unit 160 may also be arranged outside the controller device of Fig.2 so that the information regarding the presence of mobile devices within a specific range may also be provided from external devices.

The controller unit 120 receives the detection results of the mobile detector unit 160 and initiates a transmission of a special signal or detection mode signal 100 by the transmitter unit 140. As mentioned above, as soon as the mobile device has received the special signal or detection mode signal 100, a hash computing unit 60 of the mobile device computes the hash value of the memory modules 30 associated with the camera/video unit 40 and/or the hash values of the operation codes of the camera unit 40. These hash values are transmitted via the hash transmitting unit 70. The hash value as transmitted by the hash transmitting unit 70 is received by the controller device for example via the transmitter unit 140 which may also be used as a receiver unit. Thus the received hash value is forwarded to the hash database 130 via the controller unit 120 and is stored together with the identification data of the mobile device. The hash comparator unit 110 serves to compare the hash value stored in the database 130, which corresponds to the hash value computed before the special signal 100 is received with the hash value computed when a further special signal 100 is received. In other words, the hash values stored before entering premises are compared to the hash values stored after leaving the premises. If the hash comparator unit 110 detects that the hash values have changed during this time, the hash comparator unit may initiate a warning or an alert.

In an alternative embodiment of the controller device based on the controller device according to the first embodiment, the transmitter unit 140 continuously transmits a special signal 100 or transmits the special signal at regular intervals, so that a mobile detector unit 160 is not needed anymore and may be omitted. Alternatively or additionally, the mobile device may compute the hash values of the memory modules 30 and the operation codes at predetermined or regular intervals and transmit these values via the hash transmitter 70. This may be performed by sending the hash values in a query packet after which the transmitter unit 140 initiates the transmission of a special signal 100.

According to a further embodiment, the computation of the hash values of the memory modules 30 and the operation codes may be initiated by the user of the mobile device for example by pressing a specific button or a combination of buttons. The hash computing unit 40 starts computing the hash values and transmitting the computed hash values via the hash transmitter 70 to the receiver unit 140 of the controller device.

Fig.3 shows a flow chart of a method for the control of the hash function in a camera unit. The flow starts in step S 1. In step S2, there is determined whether the mobile device has entered specific premises. If the mobile device has not entered the premises, the flow proceeds to step S3 where the mobile device is left in a normal operation mode.

Thereafter, the flow proceeds to step S4 where the flow ends. If the mobile device has not entered the premises, the flow also proceeds to step S 8 where it is determined whether the mobile device leaves specific premises. If this is the case, the flow proceeds to step S9 where a special signal or detection mode signal is transmitted. Thereafter, the flow proceeds to step SlO where the hash value of the memory modules as well as that of the operation codes is determined.

Thereafter, the flow proceeds to step SI l where the hash value is transmitted from the mobile device. The flow proceeds to step S7 where the received hash values are stored and compared in the controller device or the security monitoring device. In step S6 there is determined whether the hash values have changed. If the hash values have changed, an alert is initiated in step S5 to notify the operator that a camera unit of the mobile device has been used. Thereafter, the flow proceeds to step S4 where the flow ends.

If in step S2 it has been determined that a mobile device enters premises, the flow proceeds to step S13 where there is determined whether a special signal or detection mode signal has been transmitted. If no special signal or detection mode signal has been transmitted, the flow proceeds to step S3 and the camera is left in normal operation. However, if it is determined in step S13 that a special signal has been transmitted, the flow may proceed to step S 14 where the camera unit or at least parts of the camera unit are disabled. Alternatively or additionally, the flow proceeds from step S 13 to step S15 where the mobile device is switched to a special mode or a detection mode to trace the operation of the camera. Thereafter, the flow proceeds to step S16 where the hash values of the memory modules and the operational codes are computed and are transmitted in step S 17. Thereafter, the flow proceeds to step S7 where the transmitted hash values are received by the controller device or the security monitoring device and are stored and compared. If the hash values have been transmitted in step S 17, the flow proceeds to step Sl 8 and it is indicated that the mobile device is within the premises.

In other words, a hash value of the memory block, the memory module and/or the operational code associated with a camera unit of a mobile device is determined if a special signal or a detection mode signal is received. The results of the hash computation are transmitted to a security monitoring station when the mobile device enters a specific area and when it leaves this specific area. In the monitoring station, these two hash values are compared and an alert signal is initiated if these two values do not match.

Alternatively or additionally, the mobile device may determine the hash values of the memory modules and/or the operational code associated with the camera unit at predetermined or regular time intervals and transmit these hash values to the security monitoring station. Accordingly, the security monitoring station will always be able to determine whether the camera unit of a mobile device has been used such that a warning signal may be initiated. If the mobile device determines the hash values of the memory modules and the operation code at predetermined or regular time intervals if the mobile device is switched on, any use of the camera unit will be detected even if a user switches off his mobile device when leaving the premises. The security monitoring station may compare the received hash values from the mobile devices on the spot so that any use of the camera unit may be detected immediately and a warning signal may be issued immediately. Fig.4 shows a block diagram of a part of the mobile device according to Fig.1.

Here, memory modules 30a, 30b and 30c as well as the hash computing unit 60 and data and address lines 35 are shown. The memory blocks 30a - 30c are connected to the camera unit 40 via these address lines 35. The hash computing unit 60 is coupled to the data/address lines 35 for probing for operation codes and is as well coupled to the memory blocks 30a - 30c for monitoring the data thereof. The hash values of the operation codes and the memory blocks are determined in the hash computing unit 60 which may be used as a one-way hash function generator and the determined hash values are forwarded to the hash transmitter 70 to be transmitted. In particular, as soon as the special signal 100 or a detection mode signal is received by the mobile device, the special operation mode, i.e. the detection mode for tracing the operation of the camera unit is enabled and the hash computing unit 60 will start to probe the data/address lines to determine whether any operations are performed on those memory blocks which are associated with the function of the camera unit. If any operation is performed on these memory blocks, the operation codes are probed and passed on to the hash generator. The data associated with them and stored in the memory blocks are also read and passed to the hash generator.

According to a further embodiment which may be based on any of the above- mentioned embodiments, a situation may arise where a person enters premises without being detected or registered by the controller of the premises. If such a person switches on his mobile device, the mobile device will listen to a broadcast channel and based on the actual signal strength select a base station that is transmitting the strongest signal and will then register with this base station. The base station will detect the switching on of the mobile device and can communicate this to the responsible controller. Accordingly, the base station will then forward the identification of all mobile phones registered with this station to a security monitoring system, i.e. the camera controller according to Fig.2. The security monitoring system may check whether any of the registered mobile phones has not been present in the database of the controller before. Additionally, a hash value of the memory modules and the operational codes associated with the camera unit of the mobile device may also be transmitted to the base station and forwarded to the security monitoring system when the mobile device is switched on.

In addition, the position of the mobile device may be determined for example by means of a global positioning system, a cellular telephone triangulation or other location techniques. If it is determined by this location procedure that the mobile device is within the range of the base station but outside the restricted area, then the mobile device may not be switched to a special mode during which the operation of the camera unit is traced. However, if it is determined by this localization that the mobile device is in a restricted area indeed, then the mobile device is switched to the special mode to trace the operation of the camera unit. In addition, once the mobile device is switched on and has registered with a base station, the EMSI number of the device may also be transmitted to the base station and may be forwarded to the security monitoring system to avoid any fraud on the user side by merely exchanging the SIM card. Accordingly, the security monitoring system may be able to identify the mobile device irrespective of the SIM card used by the user.

As the operation codes which are associated with the function of the camera unit are monitored and hashed, it is also possible to determine whether a user entered a restricted area with his mobile device switched on, activated the camera unit to take a picture within the restricted area and stored these data on a memory module (possibly a removable memory module) different from the one with which he entered the restricted area and leaves the restricted area with his mobile phone switched on, but with the original memory module reinstalled. Accordingly, it can be prevented that a user of a mobile phone bypasses the security monitoring.

For example, if a memory is replaced by a further memory during the operations of the camera unit of the mobile device, the hash function of the operational codes related to these camera operations is computed and is stored or transmitted accordingly, the operational codes will be different from the operational codes or in particular the hash values of the operational codes computed when the restricted area was entered. The same applies if the original memory is reinstalled in the mobile device, as the hash values of the operational codes computed when leaving the restricted area will not correspond to the hash values of the operational codes as computed when entering the restricted area.

To ensure the above-mentioned operation, operational codes related to the operation of the camera unit must be stored safely or a new hash value has to be computed each time an operation is performed. Furthermore, the hash values should be protected so that no modification of them can be performed.

The above described method for the detection of a use of a camera unit may be applicable to any portable mobile devices that comprise camera units in order to prevent the stealing of sensitive information or in order to prevent pictures from being taken in a private environment. A history of executed operation codes for special memory modules is examined and a corresponding hash function, i.e. a signature is determined. This may be triggered by an external signal.

It should be noted that the above-mentioned embodiments illustrate rather than limit the invention, and that those skilled in the art will be able to design many alternative embodiments without departing from the scope of the appended claims. In the claims, any reference signs placed between parentheses shall not be construed as limiting the claim. The word "comprising" does not exclude the presence of elements or steps other than those listed in a claim. The word "a" or "an" preceding an element does not exclude the presence of a plurality of such elements. In the device claim enumerating several means, several of these means can be embodied by one and the same item of hardware. The mere fact that certain measures are recited in mutually different dependent claims does not indicate that a combination of these measures cannot be used to advantage.

Furthermore, any reference signs in the claims shall not be construed as limiting the scope of the claims.

Claims

CLAIMS:

1. Method for the detection of a use of a camera unit in a mobile device, comprising the steps of: wirelessly receiving a signal for initiating a detection mode for detecting a use of a camera unit, - performing a hashing function on operation codes performed by the camera unit and/or a hashing function on memory modules associated with the function of the camera unit at at least a first point of time to determine first hash values, performing a hashing function on operation codes performed by the camera unit and/or a hashing function on memory modules associated with the function of the camera unit at at least a second point of time to determine second hash values, transmitting the first and second hash values, comparing the received first and second hash values, and initiating a warning signal if the first and second hash values do not match.

2. Method according to claim 1, wherein the first and/or second hash values are determined at regular time intervals if the signal for initiating the detection mode is received.

3. Method according to claim 2, wherein the determined first and second hash values are transmitted at regular intervals if the signal for initiating the detection mode is received.

4. Method according to claim 1, further comprising the steps of: determining the position of the mobile device and determining whether the location of the mobile device is within a specified area, wherein the first and second hash values are not compared if the determined position of the mobile device is outside the specified area.

5. Mobile device, comprising a camera unit (40) for taking pictures or videos; at least one memory module (30) for storing the output data of the camera unit (40), a wireless receiver unit (10) for receiving a signal to initiate a detection mode for detecting a use of the camera unit (40); - a hash computing unit (60) for computing a hash value of the memory modules (30) which are used to store the output data of the camera unit (40) and for computing a hash value on operation codes of the camera unit (40), and a transmitter unit (70) for wirelessly transmitting the hash values as computed by the hash computing unit (60).

6. Mobile device according to claim 5, wherein the hash computing unit (60) is adapted to probe data and address lines (35) between the camera unit (40) and the memory modules (30a - 30c) to find whether any operation codes have been sent over the data and address lines (35) related to the function of the camera unit, wherein the hash computing unit (60) is furthermore adapted to monitor the data of the memory modules (30a - 30c) which are associated with the function of the camera unit.

7. Mobile device according to claim 5 or 6, wherein the determined hash values of the operation codes of the camera unit (40) as well as the hash values of the memory modules (30a - 30c) are stored in a tamper-proof part of the memory modules (30).

8. Mobile device according to claim 6, wherein the transmitter unit (70) is adapted to transmit the computed hash values at regular time intervals if the signal to initiate the detection mode has been received.

9. Security monitoring system for monitoring the use of a camera unit in a mobile device, comprising: a transmitter unit (140) for wirelessly transmitting a signal (100) to initiate the detection mode for detecting the use of a camera unit and for receiving hash values as wirelessly transmitted from a mobile device, a hash database (130) for storing hash values of operational codes of a camera unit in a mobile device and/or hash values of memory modules associated with the function of the camera unit (40), and a hash comparator unit (110) for comparing the received hash values with hash values stored in the hash database (130) to detect whether the hash values have changed and to initiate a warning signal if the hash values have.

10. Security monitoring system according to claim 9, further comprising a detector unit (160) for detecting the presence of a mobile device within a specified area, wherein the transmitter unit (140) wirelessly transmits a signal to initiate the detection mode if the detector unit (160) has detected any mobile devices.