Abstract:
The invention relates to a system ( 102 ) for user authentication, particularly suited for authentication of groups of users in hospital environments. The system ( 102 ) comprises an authentication object ( 104 ) provided with a redefined geometrical pattern ( 106 ) for authenticating the user. The system ( 102 ) furthermore comprises a multi-touch surface ( 108 ) provided with a primary layer ( 112 ) and a secondary layer ( 114 ). The multi-touch surface ( 108 ) is configured for generating in response to the pre-defined geometrical pattern ( 106 ) being brought into contact with the primary layer ( 112 ) a corresponding pattern of electric interaction between the primary and secondary layers thereby enabling unique authentication based on said pattern of electric interaction.

Description:
TECHNICAL FIELD 
       [0001]    The invention relates to a system for authentication. 
       BACKGROUND ART 
       [0002]    US 2009/0085877 A1 discloses a system for user authentication employing a multi-touch screen. 
         [0003]    This system authenticates said user on the basis of multiple points of contact of his hand with the multi-touch screen since each hand has a unique contact pattern. However, it is virtually impossible for a user to exactly reproduce the unique contact pattern that provides for his or her authentication. Therefore the system is to employ relatively low standards concerning the accuracy with which said unique contact pattern needs be reproduced by the user; the system is to allow the user to reproduce its unique contact pattern with relatively large deviations. Consequently, for users with similar unique contract patterns, wrong authentication is likely to occur given the allowance of large deviations in reproducing their unique contact patterns. As a result a problem of this system is in its limited accuracy of authenticating. 
       SUMMARY OF THE INVENTION 
       [0004]    It is an object of the invention to provide a system for authentication capable of more accurately authenticating. 
         [0005]    This object is obtained by the system according to the invention, which system comprises an authentication object provided with a predefined geometrical pattern for authenticating, and a multi-touch surface provided with a primary layer and a secondary layer, which multi-touch-surface is configured for generating in response to the predefined geometrical pattern being brought into contact with the primary layer a corresponding pattern of electric interaction between said primary and secondary layers, such that authentication is based on said pattern of electromagnetic induction. 
         [0006]    By providing an authentication object having a predefined geometrical pattern, the system according to the invention enables accurately reproducing the pattern of electric interaction between the primary and secondary layers owing to the fact that the predefined geometrical pattern is a constant. Therefore the system is able to employ strict standards concerning the accuracy with which said pattern of electric interaction needs be reproduced in order to authenticate. In other words, the system enables to reproduce the predefined pattern of electric interaction with very small deviations only. More specifically, these deviations have an order of magnitude corresponding to the accuracy with which the predefined geometrical pattern is manufactured. The system thereby effectively prevents from erroneous authentication. As a result, the system of the invention increases the accuracy of authenticating. 
         [0007]    The multi-touch surface may be planar yet may be geometrically curved alike. 
         [0008]    In this text, electric interaction means mutually affecting culminating into an effect in the electrical domain, such as the flow of a current or the building up of a charge, including without limitation conductive coupling as well as capacitive coupling. 
         [0009]    The system according to the invention advantageously allows, without limitation, for authentication of a person, in which the geometrical pattern is representative for said particular person. Hence, the system according to the invention is configured for authentication of a user. The system according to the invention furthermore advantageously enables authentication of a user group by providing members of such user group with authentication objects each provided with a predefined geometrical pattern that is specifically configured for that particular user group. 
         [0010]    After authentication by the system according to the invention, a user or member of a user group may be provided with a mandate that is specifically adapted for said user or said specific user group to e.g. operate the hardware and/or software to which the system according to the invention may be connected. 
         [0011]    The system according to the invention is particularly suited for application in hospital environments. By way of example and without limitation, the following user groups need authentication in order to operate a patient monitoring device to which the system according to the invention is connectable: (i) friends and/or relatives of patients, (ii) nurses, and (iii) doctors. Friends and/or relatives, after authentication, are to receive a mandate that merely allows for investigating a limited range of measurement data generated by the patient monitoring advice connected to the patient they are related to. Nurses, once authenticated, are to receive a mandate that allows for investigation of all measurement data. Doctors, after being authenticated, are to receive a mandate that allows not only for investigating all measurement data but also for changing the settings of the patient monitoring device. 
         [0012]    The system according to the invention is advantageously capable of more accurately authenticating a person or a particular group of person without requiring for that purpose additional costly hardware such as badges and corresponding badge readers employing e.g. RFID technology. 
         [0013]    The system according to invention equally advantageously enables authentication of a content item, such as a promotional coupon or a URL, in which the geometrical pattern is representative for said content item. Consequently the system according to the invention allows for successful application in web-based offerings of services or products to specific consumers. For such web-based offering, the authentication object may be part of a promotional object of any kind (e.g. card, label) handed out to consumers. Via such promotional object with predefined geometrical pattern customers can authenticate themselves and subsequently obtain access to specific parts of a website concerning the services or products. This application of the system circumvents the need for consumers to type complete URLs thereby facilitating and hence enhancing a sales process. The system according to the invention advantageously circumvents the need for a camera, e.g. a webcam, for such web-based offerings. 
         [0014]    The predefined geometrical pattern may optionally comprise at least one protrusion, particularly a protrusion or set of protrusions that make the geometrical pattern a tactile pattern. 
         [0015]    In a preferred embodiment of the system according to the invention, the multi-touch surface comprises a resistive multi-touch surface, and the predefined geometrical pattern comprises a protrusion configured for generating a corresponding pattern of conductive coupling between the primary and secondary layers in response to the predefined geometrical pattern being brought into contact with the primary layer. Owing to the characteristics of a resistive multi-touch surface, this embodiment does not require the authentication object to have particular resistivity or conductivity characteristics in order to generate the predefined pattern of conductive coupling. As a result this embodiment has the advantage of allowing for optimization of the authentication object in terms of e.g. ergonomics and usability. 
         [0016]    In a further preferred embodiment of the system according to the invention, the system comprises a capacitive multi-touch surface, and the geometrical pattern comprises an element having a conductivity configured for generating a corresponding pattern of capacitive coupling between the primary and secondary layers in response to the predefined geometrical pattern being brought into contact with the primary layer. The element may be incorporated in the authentication object in an invisible manner. As a result the geometrical pattern is more difficult to retrieve and subsequently to falsify. Consequently this embodiment advantageously increases the security with which the system can perform authentication of the user. 
         [0017]    In a further preferred embodiment of the system according to the invention, the authentication object is incorporated in an ID card. This embodiment merges the functionality of the authentication object with that of the ID card, which ID card often is already being carried by a person particularly in e.g. hospital environments. This embodiment therefore has the advantage of increasing usability of the system. 
         [0018]    In a further preferred embodiment of the system according to the invention, the authentication object is incorporated in a primary mobile phone or a primary tablet. This embodiment merges the functionality of the authentication object with that of the primary mobile phone or primary tablet, which devices are already being carried by a person. This embodiment is therefore advantageous in that it increases usability of the system. 
         [0019]    In a further preferred embodiment of the system according to the invention, the multi touch surface is incorporated in a secondary mobile phone or a secondary tablet, and said secondary mobile phone or secondary tablet is configured for transmitting a set of data to the primary mobile phone or primary tablet in response to the predefined geometrical pattern being brought into contact with the primary layer. This embodiment is advantageous in that it enables transmission of data, including but not limited to text documents, spreadsheets and digital business cards, in an effortless yet secured way. 
         [0020]    In a further preferred embodiment of the system according to the invention, the secondary mobile phone (or smart phone) or secondary tablet is configured for transmitting a predefined set of data to the primary mobile phone (or smart phone) or primary tablet in response to the predefined geometrical pattern being brought into contact with a predefined location at the primary layer. This embodiment advantageously enables a user of the system to select in a very convenient way a particular set of data to be transmitted. 
         [0021]    In a further preferred embodiment of the system according to the invention, the multi-touch surface comprises a multi-touch screen and the predefined location at the primary layer is identified by a computer icon at the multi-touch screen and representing the predefined set of data. This embodiment is advantageous in that it further facilitates the process of selecting the particular set of data to be transferred. 
         [0022]    In a further preferred embodiment of the system according to the invention, the system is configured for authentication on the basis of a predefined displacement of the pattern of electric interaction in response to a displacement of the authentication object along the primary layer after the geometrical pattern being brought into contact with said primary layer. For the purpose of authenticating, this embodiment requires a user of the system not only to accurately reproduce the predefined pattern of electromagnetic induction; it moreover requires the user to generate a predefined displacement of said pattern. Provided the user of the system keeps such predefined displacement confidential, this embodiment effectively raises a barrier towards inaccurate authentication of a person, other than the user, having at his or hers disposal the authentication object. Therefore this embodiment advantageously increases the security of authentication. 
     
    
     
       BRIEF DESCRIPTION OF DRAWINGS 
         [0023]      FIG. 1A  schematically displays a plan view of the system according to the invention. 
           [0024]      FIG. 1B  schematically depicts a cross-sectional view of the multi-touch surface according to the invention. 
           [0025]      FIG. 2  schematically shows an embodiment in which the authentication object is incorporated in a primary mobile phone. 
           [0026]      FIG. 3  schematically depicts an embodiment wherein the multi-touch surface is incorporated in a secondary mobile phone. 
       
    
    
     DETAILED DESCRIPTION OF THE EMBODIMENTS 
       [0027]    Touch screens are frequently found in smart phones and tablets. The majority of those touch screens are multi-touch enabled since this allows for a variety of powerful user interaction principles (zoom, scroll, rotate etc.). In view of this, an embodiment of the invention proposes to provide an object with a geometrical pattern (e.g. as a tactile pattern) that can act as an identifier when held against a multi-touch screen. The multi-touch screen interprets the pattern and translates it to an identifier that represents either a user, a particular user type (e.g. “role” such as patient, nurse) or a specific content piece. 
         [0028]      FIG. 1A  schematically displays a system  102  for authentication, comprising an authentication object  104  provided with a predefined geometrical pattern  106  for authenticating. The system  102  furthermore comprises a multi-touch surface  108 . Referring to  FIG. 1B , said multi-touch surface  108  is provided with a primary layer  112  and a secondary layer  114 . The multi-touch surface  108  is configured for generating a corresponding pattern of electric interaction between said primary and secondary layers in response to the predefined geometrical pattern  106  being brought into contact with the primary layer  112 . The multi-touch surface  108  is configured for comparing, using methods and algorithms known per se, the corresponding pattern of electric interaction with reference patterns of electromagnetic induction, for example as stored in a database. Each of said reference patterns of electric interaction is uniquely linked to a respective user of the system  102  and hence performs as a user profile. The multi-touch surface  108  is provided with dimensions suitable for enabling the user to bring into contact the primary layer  112  and the geometrical pattern  106 . More specifically, the multi-touch surface  108  has dimensions enabling the edge of the multi-touch surface  108  to envelop or encase the predefined geometrical pattern  106  when brought into contact with the primary later  112 . The multi-touch surface  108  may comprise a multi-touch screen  110  known to the person skilled in the art. 
         [0029]    In another example, referring to  FIG. 1A , the geometrical pattern  106  comprises a plurality of geometrical figures i.e. a triangle  116 , a square  118 , a rectangle  120 , a straight line  122 , a hexagon  124  and a circle  126 . The geometrical pattern  106  is furthermore defined by the distances between the various geometrical plane figures, e.g. distance a, as well as by the dimensions of the various geometrical plane curves, e.g. width b of rectangle  120 . Other geometrical figures, such as ellipses and pentagons, are suitable as well for the geometrical pattern  106 . Furthermore, the geometrical pattern  106  may comprise a dot or a plurality of dots arranged in a predefined manner on the authentication object  104 . Alternatively, the geometrical pattern may comprise a single geometrical figure preferably having a high geometrical complexity such as a fractal structure. The multi-touch surface  108  may comprise a multi-touch screen  110  known to the person skilled in the art. In this specific example, the multi-touch screen  110  overlaps with the primary layer  112  and the secondary layer  114  in full. Alternatively, the multi-touch screen  110  may overlap partially with the primary layer  112  and the secondary layer  114 . 
         [0030]    In another example, the multi-touch surface  108  comprises a resistive multi-touch surface. Without limitation the resistive multi-touch surface may comprise a resistive multi-touch screen. Furthermore, the geometrical pattern  106  comprises protrusions  116 ,  118 ,  120 ,  122 ,  124  and  126  for generating a corresponding pattern of conductive coupling between the primary layer  112  and the secondary layer  114  in response to the predefined geometrical pattern  106  being brought into contact with the primary layer  112 . In this specific example the primary layer  112  and the secondary layer  114  are mutually separated by a gap. The primary layer  112  is provided with a relatively small mechanical stiffness compared to e.g. the secondary layer  114 , at least with respect to bending deformation. More specifically said relatively small mechanical stiffness is arranged for enabling that the primary layer  112  will contact the secondary layer  114 , in a pattern corresponding to the predefined geometrical pattern  106 , once the predefined geometrical pattern  106  has been brought into contact with the primary layer  112 . The protrusions  116 ,  118 ,  120 ,  122 ,  124  and  126 , being unique for a user, together constitute a tactile profile on a side of authentication object  104 . For example and without limitation, the protrusions  116 ,  118 ,  120 ,  122 ,  124  and  126  may be provided with a height in the range of 0.2 mm to 2 mm relative to the authentication object  104 . The geometrical pattern  106  may furthermore be defined by the thicknesses of the protrusions  116 ,  118 ,  120 ,  122 ,  124  and  126 . For example and without limitation, the protrusions  116 ,  118 ,  120 ,  122 ,  124  and  126  may be provided with thicknesses in the range of 0.1 mm to 1 mm. Alternatively, the protrusions  116 ,  118 ,  120 ,  122 ,  124  and  126  may be embodied by solids. Furthermore, the geometrical pattern may comprise a solid protrusion (or a plurality thereof) and a non-solid protrusion (or a plurality thereof). 
         [0031]    In a further example, the multi-touch surface  108  comprises a capacitive multi-touch surface. Without limitation the capacitive multi-touch surface may comprise a capacitive multi-touch screen. Furthermore, the geometrical pattern  106  comprises elements  116 ,  118 ,  120 ,  122 ,  124  and  126  all having a conductivity or having a range of conductivities configured for generating a corresponding pattern of capacitive coupling between the primary layer  112  and the secondary layer  114  in response to the predefined geometrical pattern  106  being brought into contact with the primary layer  112 . The elements  116 ,  118 ,  120 ,  122 ,  124  and  126  may be realized by pads of conductive materials known to the person skilled in the art. 
         [0032]    In another example, the authentication object  104  is incorporated in an ID card  128  known per se. In one possible embodiment, such a card may contain a tactile profile on one of its sides. This tactile profile causes the card to have a number of unique pressure points that contact the multi-touch screen. The order and alignment of these points give the card its unique ID. The multi-touch screen is able to keep track of multiple points that can be compared with a database of possible profiles and their corresponding users. Parameters used to generate a unique ID may for example comprise distances between points, relative location to each other, and possible shape of a point. 
         [0033]    The profile points on an authentication object such as an ID-card can for example be small thickened locations on this object (e.g. in case of a resistive touch screen), or invisible conductive pads grounded via the user (e.g. in case of a capacitive touch screen). A higher number of points on the object allows for more complex profiles, but requires the touch screen to be able to read the equal amount of points at the same time. 
         [0034]    In a further example, referring to  FIG. 2 , the authentication object  104  is incorporated in a primary mobile phone  202 . Alternatively, the authentication object  104  may be incorporated in a tablet. 
         [0035]    In a particular example, referring to  FIG. 3 , the multi-touch surface  108  is incorporated in a secondary mobile phone  302 . Alternatively, the multi-touch surface  108  may be incorporated in a tablet. In either case, the multi-touch surface  108  may comprise a multi-touch screen. 
         [0036]    In another example, in which the multi touch surface  108  is incorporated in the secondary mobile phone  302 , the secondary mobile phone  302  is configured for transmitting a set of data to the primary mobile phone  202  in response to the predefined geometrical pattern  106  being brought into contact with a predefined location at the primary layer  112 . 
         [0037]    In a specific example in which the multi-touch surface  108  comprises a multi-touch screen, the predefined location at the multi-touch surface ( 108 ) is identified by a computer icon ( 304 ), e.g. a short-cut, at the multi-touch screen and representing the predefined set of data. 
         [0038]    In a particular example the system  102  is configured for authentication of the user on the basis of a corresponding displacement of the pattern of electric interaction in response to a displacement of the authentication object  104  along the primary layer  112 , after the geometrical pattern  106  is brought into contact with said primary layer, and using methods and algorithms known per se. In this specific example the multi-touch surface  108  is configured for comparing, using methods and algorithms known per se, the corresponding displacement of the pattern of electric interaction with reference displacements of patterns of electromagnetic induction, for example as stored in a database. Each of said reference displacements of patterns of electric interaction is uniquely linked to a respective user of the system  102  and hence performs as a user profile. 
         [0039]    While the invention has been illustrated and described in detail in the drawings and in the foregoing description, the illustrations and the description are to be considered illustrative or exemplary and not restrictive. Other combinations of embodiments are feasible. It is noted that the system according to the invention and all its components can be made by applying processes and materials known per se. In the set of claims and the description the word “comprising” does not exclude other elements and the indefinite article “a” or “an” does not exclude a plurality. Any reference signs in the claims should not be construed as limiting the scope. It is further noted that all possible combinations of features as defined in the set of claims are part of the invention.