Abstract:
Systems and methods for detecting and preventing tampering of card readers are provided. In one embodiment, the invention relates to a secure card reader for detecting and preventing tampering, the secure card reader comprising a reading head configured to extract recorded data from a data card, a processing circuitry coupled to the reading head, at least one printed circuit board comprising an inner surface and an outer surface, wherein the inner surface is closer to the processing circuitry than the outer surface, at least one secure trace coupled to the processing circuitry, and a security mesh coupled to the processing circuitry, wherein the security mesh is disposed between the secure trace and the outer surface, and a housing, wherein the housing and the at least one printed circuit board form a compartment substantially enclosing the processing circuitry.

Description:
CROSS-REFERENCE TO RELATED APPLICATION(S) 
       [0001]    The present application claims priority to and the benefit of Provisional Application No. 61/565,853, filed Dec. 1, 2011, entitled, “SYSTEMS AND METHODS FOR DETECTING AND PREVENTING TAMPERING OF CARD READERS”, the entire content of which is incorporated herein by reference. 
     
    
     FIELD 
       [0002]    The present invention relates generally to card reader systems, and more specifically to systems and methods for detecting and preventing tampering of card readers. 
       BACKGROUND 
       [0003]    Card readers for facilitating various transactions have become central features of modern life and are prevalent in a number of environments. For example, during the course of a day, a user may use a card reader to conduct financial transactions at an automated teller machine, purchase gas from a point of sale terminal in the form of a fuel pump using a credit or debit card, and purchase food at the grocery store using a point of sale terminal also with a credit or debit card. In all of these instances, security is a prime concern, and an individual&#39;s data (card number, passwords, account numbers, etc.) should be kept secure and away from unintended parties. Efforts to obtain the financial information of others through tampering at these various sites employing card readers have become prevalent. As such, there is a need to counter and minimize the ability of unauthorized parties to obtain confidential information by tampering with card readers. 
       SUMMARY 
       [0004]    Aspects of the invention relate to systems and methods for detecting and preventing tampering of card readers. In one embodiment, the invention relates to a secure card reader for detecting and preventing tampering, the secure card reader comprising a reading head configured to extract recorded data from a data card, a processing circuitry coupled to the reading head, at least one printed circuit board comprising an inner surface and an outer surface, wherein the inner surface is closer to the processing circuitry than the outer surface, at least one secure trace coupled to the processing circuitry, and a security mesh coupled to the processing circuitry, wherein the security mesh is disposed between the secure trace and the outer surface, and a housing, wherein the housing and the at least one printed circuit board form a compartment substantially enclosing the processing circuitry. 
         [0005]    In another embodiment, the invention relates to a secure card reader for detecting and preventing tampering, the secure card reader comprising a reading head configured to extract recorded data from a data card, a processing circuitry coupled to the reading head, a first printed circuit board and a second printed circuit board, each comprising an inner surface and an outer surface, wherein the inner surface is closer to the processing circuitry than the outer surface, at least one secure trace coupled to the processing circuitry, and a security mesh coupled to the processing circuitry, wherein the security mesh is disposed between the secure trace and the outer surface, and a housing, wherein the housing and the first printed circuit board and the second printed circuit board form a compartment substantially enclosing the processing circuitry. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0006]      FIG. 1  is a schematic block diagram of a secure card reader system for detecting and preventing tampering in accordance with one embodiment of the present invention. 
           [0007]      FIG. 2  is a schematic block diagram of a secure card reader system for detecting and preventing tampering in accordance with another embodiment of the present invention. 
           [0008]      FIG. 3  is a perspective view of a secure fuel pump insertion card reader for detecting and preventing tampering including a front compartment enclosing a magstripe reader and a rear compartment formed of a left printed circuit board (PCB), a U-shaped housing and a right PCB (not visible but see  FIG. 5 ) in accordance with one embodiment of the present invention. 
           [0009]      FIG. 4  is a perspective view of the secure fuel pump insertion card reader of  FIG. 3  with various components removed to illustrate an inside surface of the left PCB of the reader including a processor coupled to various tamper detection devices using one or more secure traces in accordance with one embodiment of the present invention. 
           [0010]      FIG. 5  is a perspective view of the secure fuel pump insertion card reader of  FIG. 3  with various components removed to illustrate the outside surface of the left PCB and a security mesh positioned on the outside surface of the left PCB for detecting tampering in accordance with one embodiment of the present invention. 
           [0011]      FIG. 6  is a perspective view of the secure fuel pump insertion card reader of  FIG. 3  with various components removed and the left PCB made transparent to illustrate a zebra connector, a microswitch and a first push button sensor on the right PCB for detecting tampering in accordance with one embodiment of the present invention. 
           [0012]      FIG. 7  is a perspective view of the secure fuel pump insertion card reader of  FIG. 3  with various components removed and the U-shaped housing made transparent to illustrate the orientation of the microswitch and various push button sensors in accordance with one embodiment of the present invention. 
           [0013]      FIG. 8  is a perspective view of the secure fuel pump insertion card reader of  FIG. 3  with U-shaped housing and right PCB made transparent to illustrate the microswitch and various push button sensors in accordance with one embodiment of the present invention. 
       
    
    
     DETAILED DESCRIPTION 
       [0014]    Referring now to the drawings, embodiments of secure card readers employing various security features to detect and prevent tampering are illustrated. The secure card readers include processing circuitry protected by at least one printed circuit board and a housing and coupled to a card reader. The printed circuit board includes a security mesh on or near an outer surface thereof and at least one secure trace, where the security mesh is positioned between the outer surface and the secure trace. Together the printed circuit board and housing form a compartment that substantially encloses the processing circuitry. 
         [0015]    In some embodiments, the secure card readers include first and second printed circuit boards positioned to be parallel to one another and to protect the processing circuitry in conjunction with the housing. Additional tamper detection components can be installed at various locations along the secure card reader. The components can include a push button sensor, a zebra connector, a microswitch, or other suitable tamper detection component. If any of the tamper detection components, including the security mesh, reports information indicative of tampering, the processing circuitry can take appropriate measures to protect itself. These measures can include erasing memory, rending itself inoperable, and other appropriate protective measures. 
         [0016]      FIG. 1  is a schematic block diagram of a secure card reader system  100  for detecting and preventing tampering in accordance with one embodiment of the present invention. The system  100  includes processing circuitry  102  coupled to a card reader  104 , an input/output (I/O) pin block  106 , a microswitch  108 , a zebra connector  110 , one or more push button sensors  112 , a printed circuit board (PCB) mesh  114 , and one or more secure traces  116  internal to the PCB protected by the PCB security mesh  114 . In operation, the card reader  104  can extract information from a data card. 
         [0017]    In one embodiment, the card reader  104  is a magstripe reader configured to extract information from the magnetic medium of the data card. As such, the information read from the magstripe data card can include a payment account number (PAN), other information commonly stored on track  1  or track  2  of a magstripe payment card, and a magnetic fingerprint indicative of an intrinsic magnetic characteristic of the magnetic medium of the magstripe card. Techniques for extracting and comparing magnetic fingerprints are described in U.S. Pat. Nos. 6,098,881, 7,478,751, 7,210,627, and 7,377,433 and U.S. patent application Ser. Nos. 11/949,722, and 12/011,301, the entire content of each document is hereby incorporated by reference. In another embodiment, the card reader  104  is a smart card reader, or a contact block for establishing electrical contact with a smart card where the processing circuitry  102  includes an ability to extract information from the smart card via the contact block. In some embodiments, the secure card reader system  100  includes both a magstripe reader and a smart card reader. 
         [0018]    In several embodiments, the I/O pin block  106  provides a physical communication interface through which a number of signals indicative of the information extracted from one or more data cards can be communicated. In many embodiments, the extracted data card information is encrypted using one or more encryption keys for obfuscating confidential card holder or transaction information. In several embodiments, the microswitch  108  is positioned along a housing or a printed circuit board associated with the card reader system  100  and can detect removal of, or tampering with, a system component such as a housing or a PCB (e.g., unauthorized removal of the system component). In several embodiments, the zebra connector  110  is a multi-contact elastomeric connector having alternating conductive and insulating materials where the electrical connections to the conductive materials/contacts can be sustained through continued application of pressure and/or contact by a mating connector or PCB. 
         [0019]    The one or more push button sensors  112  can be positioned at various locations along the card reader system  100  for detecting tampering. One or more of the components in the card reader system  100  are mounted on or routed through a PCB. In order to protect the components from potential tampering, the PCB security mesh  114  can be located at or near an outside surface of the PCB (e.g., outer surface of the card reader system  100 ). The security mesh  114 , possibly in conjunction with the processing circuitry  102 , can detect when someone attempts to tamper with components on the inside surface of the PCB by for example, drilling through, or cutting away a portion of, the PCB. In theory, the security mesh  114  can detect any attempted penetration of the PCB by covering much or all of the surface area of the PCB. The secure traces  116  are positioned on the inside surface of the PCB (e.g., surface facing components on the inside of the reader) or on a layer internal to the PCB. In such case, the secure mesh  114  is positioned between the outside surface of the PCB and the secure traces  116  or on the outside surface. In this way, the security mesh  114  can help prevent an attacker from gaining access to the secure traces  116  or other components located on the inside surface of the PCB. In a number of embodiments, many of the component to component electrical connections in the secure card reader  100  can be implemented using the secure traces  116 . 
         [0020]    In several embodiments, the processing circuitry  102  is implemented using one or more processing components that share information (e.g., processors, microprocessors, and/or various programmable logic devices). For example, the processing circuitry  102  can include one or more secure processors that are configured to react to suspected/detected tampering by erasing preselected information from memory and/or rendering themselves partially or completely inoperable. In one embodiment, for example, the secure processor can erase encryption keys or other information that might be considered confidential or sensitive. In some embodiments, the system  100  can include one or more volatile or non-volatile memory components that store information accessible to the processing circuitry and/or other components. 
         [0021]    In one embodiment, the processor circuitry  102  responds to a breach or attempted breach by communicating the breach or attempted breach to devices connected to the magnetic read head. In one embodiment, the processor disables itself. In another embodiment, the processor erases all of its executable code stored in memory or elsewhere. In yet another embodiment, the processor reduces itself to a pseudo functional state where the only function the processor performs is reporting the breach or attempted breach. In such case, the processor can also report the type or method of the breach or attempted breach. In one embodiment of the pseudo functional state, only the executable code required to function in the pseudo functional state is preserved while all other information is erased. 
         [0022]    In the embodiment illustrated in  FIG. 1 , the secure card reader system  100  includes a single security mesh  114 , zebra connector  110  and microswitch  108 . In other embodiments, the system can include more than one of these components. In other embodiments, the secure card reader system  100  can include other tamper detection devices known in the industry. 
         [0023]      FIG. 2  is a schematic block diagram of a secure card reader system  200  for detecting and preventing tampering in accordance with another embodiment of the present invention. The system  200  includes processing circuitry  202  coupled to a magstripe card reader  204 , a smart card contact block  205 , an input/output pin block  206 , a microswitch  208 , and a zebra connector  210 . The processing circuitry  202  is also coupled to a left PCB security mesh  212   a  on a left PCB  212 , secure traces  212   b  on the left PCB  212  protected by the left PCB security mesh  212   a,  push button sensors  212   c  on the left PCB  212 , a right PCB security mesh  214   a  on a right PCB  214 , secure traces  214   b  on the right PCB  214  protected by the right PCB security mesh  214   a,  push button sensors  214   c  on the right PCB  214 , a transverse PCB security mesh  216   a  on a transverse PCB  216 , secure traces  216   b  on the transverse PCB  216  protected by the transverse PCB security mesh  216   a,  and push button sensors  216   c  on the transverse PCB  216 . In a number of embodiments, the components of the secure card reader system  200  can function in the same manner described above for  FIG. 1 , and the system can include the alternative embodiments described above for  FIG. 1 . 
         [0024]      FIG. 3  is a perspective view of a secure fuel pump insertion card reader  300  for detecting and preventing tampering including a front compartment  301  enclosing a magstripe reader (not visible but positioned within upper bezel) and a rear compartment  303  formed of a left PCB  312 , a U-shaped housing  305  and a right PCB  314  (not visible but see  FIG. 5 ) in accordance with one embodiment of the present invention. The secure fuel pump reader  300  also includes a transverse PCB  316  positioned along a dividing plane separating the front compartment  301  and the rear compartment  303 . In a number of embodiments, the front compartment  301  would be mounted such that it remains outside of a fuel pump housing, while the rear compartment  303 , including the transverse PCB  316  is mounted within the fuel pump housing. For security reasons, the inside of the fuel pump housing is meant to be kept relatively secure. However, enterprising thieves may try to gain access to the inside of the fuel pump housing to steal information from the rear compartment  303  of the reader  300 . The terms “left” and “right” as used in conjunction with the PCBs of the card reader  300  mean left and right while viewing the front compartment  301  of the reader positioned on the outside of the fuel pump housing. 
         [0025]    A data card  307  is shown positioned in a card path of the reader  300 . In some embodiments, the data card can be a magstripe card capable of storing information on a magnetic medium. In some embodiments, the data card can be a smartcard capable of storing information on one or more chips embedded within the data card. In such case, the information may be read by contacting a number of conductive terminals on the card using the appropriate protocols for accessing such stored information, as is known in the art. In a number of embodiments, the rear compartment  303  can contain a smart card reader. A I/O pin block  306  is mounted on the left PCB  312  and can be used to communicate with the secure card reader system  300 . 
         [0026]    In several embodiments, a schematic block diagram of the components of the secure fuel pump insertion card reader  300  is roughly equivalent to the schematic block diagram of  FIG. 2 . 
         [0027]    In the embodiment illustrated in  FIG. 3 , the U-shaped housing  305 , the left PCB  312 , the right PCB  314 , and the transverse PCB  316  effectively form a secure enclosure that protects a number of electronic components (e.g., processing circuitry) that could potentially be targeted by an attacker. In other embodiments, a single PCB can be used, possibly at the side or a predetermined location indicative of the greatest threat from intruders. In a number of embodiments, each of the PCBs includes a security mesh on an outer surface thereof, or within the respective PCB (see for example  FIG. 5 ). The security mesh, in conjunction with processing circuitry such as a microprocessor, can detect any number of different techniques for tampering and attempting to gain access to the rear compartment of the reader involving penetration of the respective PCB employing the security mesh. 
         [0028]      FIG. 4  is a perspective view of the secure fuel pump insertion card reader  300  of  FIG. 3  with various components removed to illustrate an inside surface of the left PCB  312  of the reader including a processor  302  coupled to various tamper detection devices using one or more secure traces  312   a  in accordance with one embodiment of the present invention. The processor  302  is also coupled, via one or more secure traces, to a pad layout  310   a  for physically and electrically contacting a zebra connector (not visible in  FIG. 4  but see  FIG. 6 ), a push button sensor  312   c,  and the I/O pin block  306 . The processor  302  is also coupled to push button sensors  316   c  via secure traces  316   b  on the transverse PCB  316  and a board to board interconnect  313 . In several embodiments, the push button sensor  312   c  is optional and can be removed from the left PCB  312 . 
         [0029]    In a number of embodiments, additional components may be mounted to the inside surface of the left PCB  312  and/or on the inside surface of the transverse PCB  316 . In some embodiments, the processor  302  can be located on another PCB such as the transverse PCB  316  or the right PCB  314  (not visible in  FIG. 4  but see  FIG. 5 ). In the embodiment illustrated in  FIG. 4 , the secure traces  312   a  are shown as being on the inside surface of the left PCB. In other embodiments, the secure traces may be positioned on an internal layer of the left PCB. In the embodiment illustrated in  FIG. 4 , a particular number of the secure traces  312   a  are shown as being on the inside surface of the left PCB  312 . In other embodiments, there may be additional traces on the left PCB, right PCB or transverse PCB. In several such embodiments, the secure mesh is positioned on an outside surface of the left PCB  312  or such that the secure mesh  312   a  (not visible in  FIG. 4  but see  FIG. 5 ) is positioned on an internal layer between the secure traces (e.g., on the inside surface or an internal layer of the left PCB  312 ) and an outside layer of the left PCB  312 . 
         [0030]      FIG. 5  is a perspective view of the secure fuel pump insertion card reader  300  of  FIG. 3  with various components removed to illustrate the outside surface of the left PCB  312  and a security mesh  312   a  positioned on the outside surface of the left PCB  312  for detecting tampering in accordance with one embodiment of the present invention. While the security mesh  312   a  is shown as being positioned on the outside surface of the left PCB  312  for ease of illustration, in many embodiments, the security mesh  312   a  is positioned on an internal layer of left PCB  312 . In such case, the security mesh  312   a  can be more difficult to observe, access, and/or defeat. The card reader  300  also includes the right PCB  314  and the transverse PCB  316 , where the right PCB  314  and left PCB  312  are oriented to be parallel to each other and perpendicular to the transverse PCB  316 . 
         [0031]    A microswitch  308  and one or more secure traces  314   b  are positioned on an inside surface of the right PCB  314  facing the left PCB  312  and coupled to a processor  302  (not visible in  FIG. 5  but see  FIG. 4 ). A security mesh (not visible) for the right PCB  314  is positioned on, or near, the outside surface of the right PCB  314 . The security mesh for the transverse PCB  316  can be located on or near a surface of the PCB  316  closest to the front compartment  301  (e.g., front of the secure card reader). A card slot housing  309  is positioned between the left PCB  312  and the right PCB  314  and may extend into or through the transverse PCB  316 . In other embodiments, the left PCB  312  and the right PCB  314  may be mounted to the transverse PCB  316  and or transverse housing  311 . In several embodiments, the left PCB  312  and the right PCB  314  are retained and supported by the U-shaped housing  305  (not visible in  FIG. 5  but see  FIG. 3 ) such that the combination of the left PCB  312 , right PCB  314 , transverse PCB  316 , and U-shaped housing  305  create a fully defined containment and the transverse PCB  316  and U-shaped housing  305  create a position setting structure to locate and retain the left PCB  312  and right PCB  314  relative to the card reader. 
         [0032]    In one embodiment, the security mesh  312   a  is a flexible grid capable of detecting puncture or other tampering. In several embodiments, the security mesh  312   a  is implemented as a matrix of conductive traces (e.g., copper). In another embodiment, the security mesh  312   a  is implemented as a matrix of conductive ink traces, such as with the Tamper Respondent Surface Enclosure of W.L. Gore and Associates of Elkton, Md. 
         [0033]    In some embodiments, flexible circuits are used to connect various components with the card reader  300 . For example, in one embodiment, a flexible circuit is used to couple the pad layout  310   a  of the zebra connector  310  with a smart card contact block  205 . In several such embodiments, the flexible circuits can include a security mesh for detecting tampering. In one embodiment, the security mesh for the flexible circuits can be a matrix of flexible conductive traces (e.g., copper). 
         [0034]    In the event that an attacker tampers with the security mesh  312   a,  the security mesh can send a signal to the processor  302  indicating the breach. In this case, tampering can include the puncture, tearing or other attempted breach of the mesh  312   a.  In one embodiment, the security mesh  312   a  can detect heat, electricity or other forms of tampering. The processor  302  can respond by initiating a destruction sequence that includes erasing encryption keys, memory and any other appropriate information. In such case, the processor  302  can also disable the encryption and/or magnetic sensor systems. 
         [0035]      FIG. 6  is a perspective view of the secure fuel pump insertion card reader  300  of  FIG. 3  with various components removed and the left PCB  312  made transparent to illustrate a zebra connector  310 , the microswitch  308  and a first push button sensor  314   c  on the right PCB  314  for detecting tampering in accordance with one embodiment of the present invention. The zebra connector  310  includes an array of conductive pads  310   a  (not visible in  FIG. 6  but see  FIG. 4 ) positioned on the inside surface of the left PCB  312  that faces the right PCB  314 . The zebra connector  310  also includes a matching array of conductive terminals and insulating material (possibly alternating the conductive terminals and the insulating material) that are configured to make un-bonded contact with the pad array  310   a  on the inside surface of the left PCB  312 . 
         [0036]    The zebra connector  310  can provide connectivity for one or more signals routed through the card slot housing  309 , such as, for example, one or more signals passed from the smart card contact block (not visible in  FIG. 6  but see  FIG. 2 ) or other signals that need to be communicated to the processor on the left PCB  312 . In addition, some contact elements on the zebra connector  310  may be dedicated to tamper detection such that any loss of the un-bonded contact along the zebra connector  310  is considered by the processor as actual or potential tampering. In a number of embodiments, the processor can take appropriate measures, as described above in the discussion of  FIG. 1 , in view of perceived tampering at the zebra connector  310 . 
         [0037]      FIG. 7  is a perspective view of the secure fuel pump insertion card reader  300  of  FIG. 3  with various components removed and the U-shaped housing  305  made transparent to illustrate the orientation of the microswitch  308  and various push button sensors ( 314   c,    316   c ) in accordance with one embodiment of the present invention. As this  FIG. 7  view illustrates, the housing  305  includes several sensor contacting structures for switching the microswitch  308  and push button sensors  316   c  into a housing installed position such that tampering may be detected if the housing is moved, detached, or partially removed. For example, sensor contacting structure  305   a  is positioned along the housing  305  such that it makes contact with an actuator button of the microswitch  308  when the housing  305  is mounted to the transverse PCB  316  (e.g., installed position). The housing also includes sensor contacting structures  305   b  and  305   c  for making contact and depressing push button sensors  316   c  mounted on the transverse PCB when the housing  305  is in the installed position. The right PCB  314  includes several traces  314   b,  which may be secure traces, for coupling the microswitch  308  and push button sensors  314   c.  The traces  314   b  are coupled to the transverse PCB  316  by another board to board connector  313 - 2  having components mounted on both the right PCB  314  and transverse PCB  316 . 
         [0038]    In one embodiment, the housing  305  is made of one or more suitable polymer materials. In one embodiment, the left PCB  312 , the right PCB  314 , and the transverse PCB  316  are made of suitable PCB materials known in the art. In one embodiment, the microswitch  308  is a KSR223GNCLFG microswitch provided by C&amp;K Components of Newton, Mass. or a CL-DA-1CB4-A2T microswitch provided by Copal Electronics of Torrance, Calif. In one embodiment, the zebra connector  310  is a 5002-08.170.475 connector provided by Fujipoly America of Carteret, N.J. In one embodiment, the board to board interconnects ( 313 ,  313 - 2 ) are MMT-106-01-L-DH-K-TR and SMM-106-02-L-D-K-TR interconnects provided by Samtec USA of New Albany, Ind. In one embodiment, the push button switches ( 312   c ,  314   c,    316   c ) are SK 3024010154011260 switches provided by Abatek (Americas), Inc. of Duluth, Ga. In one embodiment, the processor  302  is a IC0400C778BF+ provided by Maxim of Sunnyvale, Calif. 
         [0039]      FIG. 8  is a perspective view of the secure fuel pump insertion card reader  300  of  FIG. 3  with the U-shaped housing  305  and right PCB  314  made transparent to illustrate the microswitch  308  and various push button sensors ( 314   c,    316   c ) in accordance with one embodiment of the present invention. 
         [0040]    While the above description contains many specific embodiments of the invention, these should not be construed as limitations on the scope of the invention, but rather as examples of specific embodiments thereof. Accordingly, the scope of the invention should be determined not by the embodiments illustrated, but by the appended claims and their equivalents.