Abstract:
A mobile device ( 16 ) includes a transceiver ( 40 ) for mobile communication and a controller ( 44 ) configured to execute an authentication function for authenticating a registered user of the device, in which the device ( 16 ) has only a single operating element ( 48 ), the functionality of the single operating element ( 48 ) is limited to activating and deactivating the authentication function, the authentication function has the transceiver logged-on to a mobile communications network and enabling a detection of an active state and/or a location of the mobile device via the mobile network, and the operating element ( 48 ) and the transceiver ( 40 ) constitute the only data input and output ports of the controller ( 44 ).

Description:
BACKGROUND OF THE INVENTION 
     The invention relates to a mobile device comprising a transceiver for mobile communication and a controller configured to execute an authentication function for authenticating a registered user of the device. 
     In transactions in which a user communicates with a remote transaction partner via a communication channel such as the Internet, it is important to assure that an individual that identifies itself as an authorised user is actually the person it alleges to be. For example, when a user makes an online bank transaction in which he identifies himself as the owner of a certain account and requests that an amount of money is remitted to some other account, an authentication method is needed for verifying the identity of the requestor. Other examples of transactions where an authentication of the user should be required are transactions in which a user asks for online access to a database or other online services that involve sensitive data. Another example would be a transaction for operating a door opener that provides physical access to a secure area or room. 
     WO 98/25371 A1 discloses a mobile device of the type indicated above, wherein the authentication function includes prompting the user to confirm the transaction request. 
     US 2006/288233 A1 discloses a mobile device with a biometric authentication function. 
     WO 2007/072001 A1 discloses an authentication method and a mobile device wherein an authentication device responds to the transmission of a user identification with sending an authentication token to a terminal from which the transaction has been requested. This token may for example be encoded in a digital image to be displayed on a display of the terminal. The authentication function in the mobile device is configured to capture this digital image and send it back to the authentication device via the mobile communication channel. 
     In this way, it can be confirmed that the person carrying the mobile device, e.g. a mobile telephone, is actually present at the location of the terminal from which the transaction has been requested. Thus, as long as the user is in control of his mobile device, the authentication method assures that no third party can fake the identification data of this user and perform any transactions in his place. 
     SUMMARY OF THE INVENTION 
     It is an object of the invention to provide a mobile device that is suitable for authentication purposes and is of low complexity and easy to handle. 
     In order to achieve this object, the mobile device according to the invention has only a single operating element, the functionality of said single operating element is limited to activating and deactivating the authentication function, said authentication function consists in having the transceiver logged-on to a mobile communications network and enabling a detection of an active state and/or a location of the mobile device via the mobile network, and the operating element and the transceiver constitute the only data input and output ports of the controller. 
     This device can be used, for example, for an authentication method wherein the authentication function that is implemented in the mobile device is normally inactive and is activated by the user only preliminarily for the transaction, and wherein the authentication device authenticates the user to a transaction only when a predetermined time relation exists between the transmission of the user identification and the active state of authentication function. 
     In this method, the complexity of the authentication function can be reduced significantly. In the extreme, all that has to be required from the authentication function is to permit the authentication device to detect whether or not this function is active. Likewise, the only activity that is required from the user for authentication purposes is to activate the authentication function at a suitable timing for the transaction. Once the active state of the authentication function has been detected, this function is returned into the inactive state, either automatically or manually by operating the operating element once again. The “predetermined time relation” may imply that the authentication function is active at the moment at which the user identification is sent from the terminal. As an alternative, the predetermined time relation may imply that the authentication function is activated within a certain (preferably short) time window after the transmission of the user identification or, conversely, that the user identification is transmitted within a specified time window after the authentication device has detected that the authentication function is active. 
     Since the authentication function is normally inactive, the authentication will almost certainly fail when a third party fraudulently identifies itself as the user in order to initiate a transaction. Then, the authentication would be successful only in the very unlikely event that the true user happens to activate the authentication function of his mobile device just in the right moment. Even in this unlikely case the fraud could be detected because the user will only activate the authentication function when he wants to make a transaction himself. Consequently, the authentication device would detect a coincidence between one activation of the authentication function and two transaction requests (normally launched from different terminals), and this would cause the authentication device to have the transactions denied or reversed. Thus, notwithstanding the low complexity, the method according to the invention offers a high level of security. 
     As an alternative or in addition, the authentication device may check whether there is a predetermined spatial relation between the mobile device and the terminal. 
     More specific optional features of the invention are indicated in the dependent claims. 
     It is preferred that the mobile device does not have to have any specific hardware for capturing or outputting information. All that is required from the mobile device is that it can be activated for a certain (preferably short) period of time and is capable of connecting to a mobile communications network where it has an address that is linked to the identification data of the user, so that the authentication device, when it receives the user identification from the terminal, is capable of checking whether the authentication function of the mobile device with the associated address is active. To that end, it is not even necessary that there is any actual communication between the authentication device and the mobile device. For example, when the mobile device has a mobile telephone (GSM) transceiver, the activation of the authentication function may just consist of activating that transceiver, so that it connects to the nearest Base Station Subsystem (BSS) of the mobile network. As a result, the mobile device will be identified by its device identifier (IMSI), and information on the active state of the mobile device and on the GSM-cell in which it is located will be entered into a Home Location Register (HLR) of the mobile network. Thus, the authentication device may check the active or inactive state of the mobile device and may locate the same just by querying the HLR. 
     The mobile device may have a plurality of mobile addresses (e. g. mobile telephone numbers) and may even be capable of communicating via a plurality of different mobile networks. In that case, it is preferable that each mobile address is assigned to a different type of transaction (e. g. one telephone number for authenticating bank transactions and another one for authenticating access to a data network), and the authentication function or a plurality of authentication functions are adapted to be activated and deactivated separately for each type of transaction. 
     In a modified embodiment, for enhanced safety, a plurality of mobile addresses may be assigned to one and the same type of transaction, and the mobile device and the authentication device use identical algorithms for changing from time to time the mobile address that is to be used for authentication purposes. 
     Optionally, the device according to the invention may have a positioning function permitting to locate the mobile device, and optionally a function for sending the detected location via the transceiver to the authentication device. 
     It may be advantageous when there is no communication whatsoever between the mobile device and the authentication device, nor between the mobile device and the terminal or any other entity, because, when there is no communication, there is no possibility that this communication may be tapped and may be used to outsmart the security system. 
     Preferably, the electronic components of the device are protected against both electronic and mechanical access. 
     The device may also have a self-destruction function configured to be activated by an attempt of enforced access. 
     These features will assure that nobody can enforce access to the data processing system in order to read-out program code or data that are stored therein and might be used for imitating the mobile device. 
     For example, the self-destruction function may be triggered by an event in which the body of the device is broken to expose the data processing system (chip) and may assure that, in that event, or the program code and the data are erased. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       Embodiments of the invention will now be described in conjunction with the drawings, wherein: 
         FIG. 1  is a block diagram illustrating an authentication method; 
         FIG. 2  is a time diagram illustrating the authentication method; 
         FIG. 3  is a block diagram illustrating an example of a communication scheme for an embodiment of the invention; 
         FIG. 4  is a view of a mobile device according to the invention; 
         FIG. 5  is a sectional view of the device shown in  FIG. 4 ; 
         FIG. 6  is a view of a mobile device according to another embodiment; and 
         FIG. 7  is a simplified diagram illustrating a modification of the authentication method. 
     
    
    
     DETAILED DESCRIPTION 
     As is shown in  FIG. 1 , a transaction terminal  10 , e.g. a banking machine, communicates with a remote transaction partner  12 , e.g. a bank, via a first communication channel  14  which may be a wireline or wireless channel. A mobile device  16  communicates with an authentication device  18  via a second communication channel  20  which preferably includes a wireless link, e.g. a mobile telephone network. The authentication device  18  may be installed in the premises of the transaction partner  12  or may be configured as a separate entity communicating with the transaction partner  12  via a third communication channel  22 . 
     The mobile device  16  is carried by a user who is registered as a subscriber to the mobile telephone network forming the communication channel  20 . The authentication device  18  is formed by data processing hardware and software and includes a database that stores a user ID of the user and the mobile telephone number (or any another mobile address) of the mobile device  16  of that user. 
     It shall now be assumed that the user wants to make a bank transaction via the terminal  10 . To that end, the user operates the terminal  10  and sends a transaction request to the transaction partner  12 . That request includes a step A of transmitting the user-ID to the transaction partner  12 . In a step B, the transaction partner  12  forwards the user-ID to the authentication device  18 . Thereupon, the authentication device  18  retrieves the mobile telephone number and/or the IMSI of the user and contacts the mobile device  16  or at least the mobile telephone network to check whether or not the mobile device  16  or a certain authentication function implemented therein is active (step C). When it is confirmed in step D that the authentication function is active, the authentication device  18  sends an authentication signal to the transaction partner  12  (step E). The authentication signal preferably includes the user-ID that has been sent in step B and informs the transaction partner that this specific user is authenticated to the requested transaction. Thereupon, the transaction between the user and the transaction partner  12  will be performed via the terminal  10  (step F). 
       FIG. 2  shows a time diagram illustrating one embodiment of the authentication method that has been outlined above. 
     At a time t1, the user who wants to request a transaction activates his mobile device  16 . At a time t2, the sequence of steps A-B-C-D-E is performed to authenticate the user. Since, at this time, the mobile device  16  is actually active, the authentication is successful. Then, at a time t3, the mobile device  16  is deactivated either manually or automatically by a self-deactivation function implemented in the device  16 . As another alternative, a command to deactivate the mobile device  16  may be sent by the authentication device  18  when the user has been authenticated successfully. 
     Preferably, the time interval from t1 to t3 in which the mobile device  16  is active will be relatively small, e.g. only a few minutes or seconds. When it is found in steps C and D that the mobile device  16  (or at least the authentication function thereof) is not active, it must be assumed that the person who is identified by the user-ID and is in control of the mobile device  16  does not actually want to request a transaction, and it must therefore be concluded that the user-ID sent in step A has been faked by an unauthorised third party. In that case, the authentication is denied in step E. 
     In this embodiment, the authentication process may optionally include additional steps of communication between the mobile device  16  and the authentication device  18 . Such communication protocols for authentication purposes are generally known in the art. 
     For example, the mobile device may use a pre-programmed algorithm to generate an identification code and send it to the authentication device. The pre-programmed algorithm is known to the authentication device and is used there to verify the identity of the mobile device, independently of its IMSI. The identification code may for example be a number from a list of “TAN” numbers that is stored in the mobile device, the algorithm being configured such that each number is used only once. On the other hand, in order to permit an infinite number of transactions, the identification codes may be generated dynamically, possibly with use of data such as the current date or the time of the day. In yet another embodiment, the identification code may be an encrypted password or an encrypted combination of a password with time and date data, the encryption being based on a dynamically varied encryption parameter that is sent from the authentication device. 
     The authentication will be successful only when the authentication device finds the identification code to be valid. In any case, the authentication will be denied whenever it is found that the authentication function of the mobile device  16  is not active at the right time. 
       FIG. 3  illustrates a communication scheme in which the first communication channel  14  and the third communication channel  22  are formed by the Internet, for example. The authentication device  18  is installed remote from the transaction partner  12  and is run by a Trusted Third Party that is independent from the transaction partner  12 . The second communication channel  20  is formed by a mobile telephone network including a Home Location Register (HLR)  32  and a plurality of Base Station Subsystems (BSS)  34  only one of which has been shown in  FIG. 7  and each of which serves one or more mobile telephone cells  36 . 
     In this embodiment, the authentication device  18  identifies the mobile cell  36  in which the device  16  is currently located, and the user is authenticated to the transaction only when the mobile device  16  is found to be located in the cell  36  that accommodates also the terminal  10  from which the transaction has been requested. Thus, a false authentication is possible only when the user-ID is sent from a certain terminal  10  at the right moment and, additionally, the mobile device  16  of the true user happens to be located in the vicinity of that terminal  10 . 
     If the mobile network  20  supports Location Based Services (LBS), then the current location of the mobile device  16  may be identified with much higher spatial resolution, and a successful authentication may require that the mobile device  16  is only a few hundreds or a few tens of meters apart from the terminal  10 . 
     In yet another embodiment, the mobile device  16  may include a GPS function, and the authentication function may be configured to send the current GPS coordinates of the mobile device  16  to the authentication device  18 . 
       FIGS. 4 and 5  show an example of a mobile device  16  according to the invention that is dedicated to the authentication purpose. This device  16  has a single casing or body  38  which accommodates a wireless transceiver  40  (e.g. a mobile telephone transceiver) with an antenna  42 , an electronic controller  44  (data processing system), a rechargeable battery  46 , and a battery charge control lamp  47 . 
     A device identifier (ISMI) is permanently stored in the controller  44  which may have the only function to activate and deactivate the transceiver  40  so that the latter may connect and identify itself to the nearest BSS  34 . Only a single ON-switch  48  (operating element) is formed in the surface of the body  38 . The ON-switch  48  may simply be formed by a button, so that the user may activate the authentication function (i.e. the transceiver  40 ) by pressing the button. As an alternative, the ON-switch may be formed by an input device for inputting some secret code (e. g. a PIN) or by a biometric sensor such as a fingerprint sensor or iris recognition sensor, so that the transceiver will be activated only when the identity of the user has been confirmed. As is shown in  FIG. 5 , a buzzer  49  is provided for giving an acoustic feedback when the authentication function has been activated successfully by pressing the ON-switch  48 . 
     The body  38  has relatively small dimensions and is attached to a key ring  50  so that it may conveniently be carried along at a bunch of keys of the user. 
     Projecting from one end of the body  38  is a male socket  52  (e.g. an USB socket or micro-USB socket) which is connected to the battery  46 , so that the battery may be recharged by plugging the device  16  into a female USB socket of a computer, a mobile phone or the like. The male socket  52  is covered and protected by a removable cap  54 . In the example shown, the cap  54  forms a female socket  56  that is open to the outside and is internally connected to another female socket  58  that accommodates the male socket  52 . Thus, the battery  46  may also be recharged by plugging a male USB or micro-USB connector of a power source into the socket  56 . 
     As is shown in  FIG. 5 , the body  38  is a massive plastic body with the transceiver  40 , the controller  44  and the battery  46  cast therein. Thus, physical access to these components, especially the transceiver  40  and the controller  44 , is not possible without destroying the body  38 . 
     In a modified embodiment, the controller  44  may include a memory with program code and data for more complex authentication functions, e. g. a function for generating and transmitting a device identification code, as has been described above. However, the controller has no electronic contacts that would provide a possibility to read-out the contents of the memory. Optionally, the controller  44 , especially the memory thereof, may be configured such that all stored contents are erased as soon as the body  38  is broken and someone tries to remove the controller therefrom. Thus, the authentication data that may be stored in the memory of the controller  44  are reliably protected against copying. 
       FIG. 6  shows an example of a mobile device  16 ′ that is dedicated only to authentication purposes but supports two different authentication procedures for two different types of transaction. The device  16 ′ has two SIM cards  60 ,  60 ′ (or other memory devices) which store different sets of access data. Thus, each of the SIM cards has its own mobile telephone number which may even belong to two different mobile networks. Each mobile telephone number is assigned to a different one of the types of transaction. The two mobile numbers may be registered in two different authentication devices or my be registered in the same authentication device along with information specifying the type of transaction for which they shall be used. 
     Further, the device  16 ′ has two buttons  48  and  48 ′ for selectively activating one of the two SIM cards  60 ,  60 ′. Thus the user may specify the type of transaction he wants to perform by pressing either the button  48  or the button  48 ′ in order to activate the related SIM card and, implicitly, the related authentication function. The controller  44  will then automatically deactivate the authentication function (SIM card) after a certain time interval. 
     As an alternative, the device  16 ′ may have a plurality of SIM cards (or other Mobile Network Identification Numbers such as IMSI, phone No. and the like) but only a single switch  48  for activating the authentication function. Then, a certain algorithm that is stored in the controller  44  is used for deciding which of the SIM cards is to be used, e.g. depending upon the date, the time of the day or the like. An identical algorithm is used in the authentication device  18 , and a successful authentication is possible only when both the mobile device and the authentication device use the same contact data associated with the determined SIM card. 
       FIG. 7  illustrates a useful modification that may be implemented in any of the authentication methods discussed above. Normally, the request for authentication sent from the terminal  10  to the transaction partner  12  will include not only the user ID but also a password showing that the user is actually entitled to the service he is requesting. However, in the embodiment shown in  FIG. 7 , this password is not transmitted via the first communication channel  14  but via the second or third communication channel. This reduces the risk of the combination of password and user ID being captured by tapping one of the communication channels. 
     In the embodiment shown in  FIG. 7 , the mobile device includes a password generator that generates a dynamically changing password according to a certain algorithm that is mirrored by the authentication device  18 . Thus even if the IMSI has been captured by a IMSI catcher, the fraud can still be detected because of a mismatch of the passwords generated in the mobile device  16  and the authentication device  18 , respectively. Preferably, the password sent via the communication channel  20  is encrypted. The decrypted password may then be passed on to the transaction partner  12 . 
     In the example shown, however, the password generated in the mobile device is a universal password that is used for each authentication process regardless of the transaction partner and the type of service involved. Then, based on information on the specific type of service, as transmitted from the transaction partner  12  in step B, if the authentication is successful, the authentication device  18  automatically converts the universal password into a specific password that is pertinent for the type of service.