System for securing a magnetic card reader, corresponding magnetic card reader and electronic device

Abstract

A system for securing a magnetic card reader, including a surface-mounted magnetic reader head, via at least one mounting end, on a flexible printed circuit. The flexible printed circuit includes: at least one first layer for transporting analogue signals of the magnetic reader head; at least one layer having a plurality of tracks connected to the ground, called ground layer, covering the analogue signals of the first layer; and at least one dynamic security layer covering the ground layer.

Claims

1. A securing system for securing a magnetic card reader comprising a surface-mounted magnetic reader head, via at least one mounting end, on a flexible printed circuit, said securing system comprising: said flexible printed circuit, which comprises: at least one first layer for transporting analogue signals from said magnetic reader head; at least one layer comprising a plurality of tracks connected to ground, called a ground layer, covering said analogue signals of said first layer; and at least one dynamic security layer covering said ground layer.

2. The securing system according to claim 1, wherein said ground layer also covers at least said mounting end of said magnetic reader head on said flexible printed circuit.

3. The securing system according to claim 1, wherein said dynamic security layer comprises a mesh formed of a plurality of conductive tracks, said mesh generating a random digital signal.

4. The securing system according to claim 3, wherein at least one track connected to the ground is nested in said plurality of tracks of said mesh.

5. The securing system according to claim 4, wherein routing of said at least one nested ground track is implemented so as to absorb at least some interferences generated by said dynamic security layer.

6. The securing system according to claim 1, wherein routing of said plurality of tracks of said ground layer is implemented so as to absorb at least some interferences generated by said dynamic security layer.

7. The securing system according to claim 5, wherein the routing is adapted to routing of the tracks of said transporting layer.

8. A magnetic card reader comprising a surface-mounted magnetic reader head and a securing system for securing said magnetic card reader, via at least one mounting end, on a flexible printed circuit, said securing system comprising: said flexible printed circuit, which comprises: at least one first layer for transporting analogue signals from said magnetic reader head; at least one layer comprising a plurality of tracks connected to ground, called a ground layer, covering said analogue signals of said first layer; and at least one dynamic security layer covering said ground layer.

9. The securing system according to claim 6, wherein the routing is adapted to routing of the tracks of said transporting layer.

10. An electronic payment terminal, comprising: a magnetic card reader comprising a surface-mounted magnetic reader head; and a securing system for securing said magnetic card reader, said securing system comprising: a flexible printed circuit comprising: at least one mounting end secured to the magnetic card reader; at least one first layer for transporting analogue signals from said magnetic reader head; at least one layer comprising a plurality of tracks connected to ground, called a ground layer, covering said analogue signals of said first layer; and at least one dynamic security layer covering said ground layer.

11. The securing system according to claim 1, wherein the at least one layer comprising the plurality of tracks connected to ground is positioned between the at least one first layer for transporting analogue signals and the at least one dynamic security layer covering said ground layer.

Description

FIGURES

(1) Other characteristics and advantages of the invention will appear more clearly upon reading the following description of a preferred embodiment, given as a single illustrative and non-limiting example, and the appended drawings, among which:

(2) FIG. 1 illustrates an example of a securing system according to one embodiment of the invention;

(3) FIGS. 2a to 2d illustrate the different layers of the secure flexible printed circuit according to one embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

(4) The general principle of an exemplary embodiment of the invention is based on the modification of the flexible printed circuit on which is surface-mounted a magnetic reader head to ensure the securing of this magnetic reader head, and therefore of the magnetic card reader, against possible attacks intended to spy on the data of this magnetic reader head (for example, sensitive data read from the magnetic card inserted in the magnetic card reader comprising confidential transaction data).

(5) To do this, this modified flexible printed circuit comprises at least the three following layers: a layer for transporting analogue signals from the magnetic reader head; at least one dynamic security layer comprising a plurality of tracks in the form of a mesh generating a random digital signal, and at least one ground layer inserted between the transporting layer and the dynamic security layer.

(6) Thus, rather than adding a specific electronic component which protects a predefined zone, the system proposed consists both: of using a magnetic reader head surface-mounted on a flexible printed circuit, making it possible to simplify, in particular, the architecture of the magnetic card reader, and of securing this magnetic reader head and the signals travelling in the flexible printed circuit on which it is mounted, thanks to a specific architecture of this flexible printed circuit itself.

(7) This specific architecture is in particular illustrated, according to the specific embodiments of the invention, by FIGS. 1 and 2a to 2d described below. The present solution can be implemented in all electronic devices comprising a magnetic card reader and responding to security constraints, like for example electronic payment terminals, authentication or identification devices or also content reader devices.

(8) According to one embodiment of the invention, illustrated for example in FIG. 1, the securing of the magnetic card reader is ensured by a dynamic security layer L3 composed of a mesh making it possible, not only of detecting any intrusion cutting the tracks thereof, but also of disturbing any attempt of spying data of the magnetic reader head by generating a random digital signal (for example, a signal going from 0 volts to 2 volts randomly).

(9) This dynamic security layer L3 could lead to interferences with the signals from the magnetic reader head travelling over the layer L1, a ground layer L2, also called shielding, is inserted between the transporting layer L1 and the dynamic security layer L3, so as to absorb some of the interferences potentially generated by the dynamic security layer L3.

(10) Finally, an additional shielding is ensured by the nesting/embedding of at least one track connected to the ground in the tracks of the mesh of the dynamic security layer L3.

(11) The flexible printed circuit 11 on which is mounted the magnetic reader head 10, via one or more mounting ends T, therefore comprises at least these three couches L1, L2 and L3.

(12) Thus, the proposed solution makes it possible, not only: to simplify the architecture of the magnetic card reader by using a magnetic reader head surface-mounted on a flexible printed circuit and therefore by avoiding the need to add a specific electronic component or by avoiding a specific mounting process; to ensure the security of the surface-mounted magnetic reader head thanks to a dynamic mesh, and to the nesting/embedding of the mesh itself with the ground; while reinforcing the preservation of the integrity of the low-amplitude analogue signals from the magnetic reader head by limiting the impact of the dynamic signal of the mesh, thanks to a ground layer inserted between the analogue signals and the mesh, and thanks to an nesting/embedding of the ground within the mesh itself.

(13) It must be noted, that according to an embodiment making it possible to obtain an optimal efficacy, the (ground) layer L2 and (dynamic security) layer L3 cover, not only fully, the analogue signals from the magnetic reader head, but also the mounting ends T of the magnetic reader head on the secure flexible printed circuit.

(14) To do this, the different layers are assembled during the manufacturing of the secure flexible printed circuit. Thus, the secure flexible printed circuit is already “pressed” with the different layers during the assembly on the magnetic reader head.

(15) This embodiment is, for example, illustrated in FIGS. 2a to 2d, representing respectively the layers L1, L2 and L3, as well as the three superposed layers.

(16) More specifically, in FIG. 2a corresponding to the layer L1, the low part represents some of the tracks for transporting analogue signals from the magnetic reader head, while the high part represents a part of a mounting end T of the magnetic reader head, making it possible for the data to be read by the magnetic head to travel over the tracks described above, in view of them being processed by the other elements of the magnetic card reader and of the electronic device comprising this magnetic card reader. FIG. 2a illustrates an example of specific configuration of the tracks of the analogue signals from the magnetic reader head, configuration from which the ground layer L2 and dynamic security layer L3 are specified in view of both an optimal securing of these signals from the magnetic reader head and a maximum absorption of the interferences due to this securing by the layer L3.

(17) Thus, as illustrated in FIG. 2b representing the ground layer L2, the tracks connected to the ground are routed so as to fully cover the tracks of the layer L1, as well as the mounting end T of the magnetic reader head, illustrated on the high part of FIG. 2b. In this manner, all the analogue signals travelling from the magnetic reader head to the remainder of the magnetic card reader are protected from possible interferences generated, not only by the dynamic security layer L3, but also by other elements of the magnetic card reader or of the electronic device itself. Thus, it can actually be noted, that the ground tracks of this layer L2 follow the same design as the tracks for transporting the analogue signals from the magnetic reader head of the layer L1.

(18) Finally, as illustrated in FIG. 2c, a third layer L3 is added, composed of a dynamic mesh, i.e. a plurality of tracks, generating a random signal. This dynamic security layer L3 also comprises tracks connected to the ground, for example via the different points m illustrated in FIGS. 2a to 2d, so as to reinforce the absorption of the interferences generated, in particular by the layer L3 itself. Even then, the tracks of the dynamic mesh and the nested/embedded ground tracks are routed so as to make it possible, not only for an optimal securing of the analogue signals of the layer L1, but also an optimal absorption of the possible interferences. Thus, it can actually be noted, that the tracks of this layer L3 also follow the same design as the tracks for transporting the analogue signals of the magnetic reader head of the layer L1. The mesh of this layer L3 also covers, according to this embodiment, the mounting ends T of the magnetic reader head.

(19) Finally, FIG. 2d illustrates these three superposed layers L1, L2 and L3, according to one embodiment of the securing system according to the invention. Likewise, as for FIGS. 2b and 2c, it can be noted, that the overall design of these three superposed layers corresponds to that of the tracks for transporting the analogue signals from the magnetic reader head of the layer L1, such that these analogue signals are not only secured against external attacks thank to the dynamic mesh of the layer L3, but also protected from interferences, in particular generated by this layer L3, thanks to the layer L2 and to the ground nested/embedded in the layer L3.

(20) Other architectures or designs of the tracks of the analogue signals from the magnetic reader head are possible of course, according to the architectural constraints of the magnetic card reader itself, or of the electronic device, and the routing of the tracks of the layers L2 and L3 are thus consequently suitable, so as to achieve the aim of securing and protecting against interferences.