DE19816572A1 - Security module to prevent manipulation of data - Google Patents

Abstract

The data security unit has a circuit board (11) on which are mounted a security module (1), a battery (10) and a manipulation circuit (9). The elements are embedded in an X ray absorbent material (2). Positioned over the electronics is an X ray detector (6) and an optical detector (5) that are used together with the manipulation element to prevent illegal changes

Description

The invention relates to an arrangement for a security module in particular to prevent reading or unauthorized persons Manipulation of security-relevant data. This data can be safe Safety-relevant parts of a machine program, credit values or other security-related functions.

Such a module is used for example in ASICS in franking machines cards or smart cards for money transactions or in ATMs set.

For general protection and protection against manipulation the security module usually with a hardening potting surround mass, see EP 0 717 370 A2. The sealing compound is in the Usually an epoxy resin or another suitable plastic.

This makes manipulation difficult, but not prevented. To manipulate such a security module to be able to do this, one would first have the same X-ray examination  undergo and then suitable for access Grind or drill open areas.

Furthermore there is an influence on the electrical connection conclusions possible.

Another known protective measure is the safe unit with a film with a meandering conductor high To enclose packing density and to couple it electrically, see Bennet Yee "Using Secure Coprncessors" May 1994 CMU-CS- 94-149, School of Computer Science Carnegie Mellon University Pittsburgh, page 7.

The conductor is powered by a long-life battery. When through disconnection at any point the circuit is interrupted and consequently the security-relevant data in the security mo dul manipulated to the point of complete deletion of the same.

The purpose of the invention is to improve the manipulation safety.

The invention has for its object to provide an arrangement which has the effect that x-ray examinations are prevented and sepa Do not try to drill or grind desired success.

According to the invention, this object is achieved according to the main claim solved. Further advantageous features of the invention are the Unteran to take sayings.

Due to the optional staggering of protective sleeves and detectors become a safer one depending on the need and the right to spend Protection against unauthorized manipulation achieved.

The invention is explained in more detail below using the exemplary embodiment explained.

In the figure is a longitudinal section through an arrangement according to the invention shown.

The illustration is for simplification and easier understanding carried out schematically.  

Referring to FIG. 1, the inventive arrangement of:

• a security module 1 together with manipulation circuit 9 and battery 10 , which are placed together on a module circuit board 11 and are electrically connected to one another,
• a sheath 2 absorbing the x-rays surrounding the aforementioned assemblies
• an X-ray detector 6 , a meandering electrical conductor 4 and at least one light detector 5 which is coupled to a light conductor 51 and which are all electrically connected to the module board 11 ,
• - Another, opaque shell 3 and
• - An X-ray absorbing housing 7 surrounding the aforementioned components, which is placed on a circuit board 8 , which in turn is electrically connected to the module circuit board 11 .

The manipulation circuit 9 is obtained or programmed so that, in the event of a malfunction, security-relevant data are manipulated in a predetermined manner such that the security module no longer works properly. The deliberate manipulation can also consist in the deletion of all security-relevant data. The battery 10 is used to supply power to the meandering conductor 4 and the manipulation circuit 9 and is designed as a long-life battery.

The shell 2 consists of a casting resin, which is mixed with an X-ray absorbing filler made of lead and copper alloys and optionally other fillers. The first filler is preferably a mixture of 85% red lead -Pb ₃ O ₄ - and 15% cuprite -Cu ₂ O-. Quartz powder, glass balls or glass fiber are used as additional fillers.

The casing 2 can alternatively also be designed as a lead jacket housing.

The x-ray detector 6 outside the casing 2 is directly electrically connected to the module board 11 and, via the same, to the manipulation circuit 9 or to the security module 1 .

The same applies to the meandering conductor 4 and the light detector 5 .

The shell 3 is only designed as an opaque housing, with which in addition to its main function - when opening the light detector 5 - on the one hand a visual protection of the arrangement and on the other hand protection against contact of the included detectors is achieved.

In this case, the housing 7 is preferably electromagnetically shielded - plastics with a copper and iron coating - and contains a lead plate 71 which shields the subsequent assemblies on the inside. It can also be designed entirely as a lead housing.

The mode of operation is described as follows.

If the entire arrangement is irradiated with X-rays and / or exposed to other electromagnetic fields, nothing can be seen due to the nature of the housing 7 and the X-ray detector 6 remains inactive. The housing 7 serves primarily as protection during routine investigations by customs or other control services. If it is ensured that such tests are not carried out for the device, the housing 7 can be omitted. If the housing 7 is removed and the part with the casing 3 is treated with X-rays, the X-ray detector 6 is activated and, consequently, the security-relevant data is falsified or deleted.

In the experiment by boring the casing 3 , both the light detector 5 and the conductor 4 are triggered and the security-relevant data in an analogous manner as described above are made unrecognizable and therefore unmanipulable for other purposes. Since the light detector 5 is coupled to a light guide 51 which can cover the entire surface, any incidence of light is effective.

Finally, the first inner shell 2 already forms a secure barrier against X-ray examinations.

Reference list

1

Security module

11

Module board

2nd

Cast resin sleeve with X-ray absorbing filler

3rd

opaque shell

4th

meandering electrical conductor

5

Light detector

51

Light guide

6

X-ray detector

7

X-ray absorbing housing

71

X-ray absorbing plate in the housing

7

8th

circuit board

9

Manipulation circuit

10th

battery

Claims (7)

1. Arrangement for a security module to prevent reading or unauthorized manipulation of security-relevant data, characterized in that
that the security module ( 1 ) is surrounded by at least one x-ray absorbing shell ( 2 ) and
with means ( 4 , 5 , 6 ) for the targeted manipulation of security-relevant data in the case of mechanical intervention and / or X-ray radiation is seen. 2. Arrangement according to claim 1, characterized in that the sheath ( 2 ) consists of lead. 3. Arrangement according to claim 1, characterized in that the shell ( 2 ) consists of a casting resin with an X-ray absorbing filler made of lead and copper compounds and optionally other fillers. 4. Arrangement according to claim 3, characterized in that a mixture of 85% red lead -Pb ₃ O ₄ - and 15% cuprite -Cu ₂ O- and as additional fillers either quartz powder, glass balls or glass fiber are used. 5. Arrangement according to claim 1, characterized in
that the security module ( 1 ) is surrounded by a further, opaque shell ( 3 ) and
that a meandering electrical conductor ( 4 ) or a light detector ( 5 ) together with light guide ( 51 ) or an X-ray detector ( 6 ) or combinations thereof are arranged in the transition region between this sheath ( 3 ) and the X-ray absorbing sheath ( 2 ) which are electrically connected to the security module ( 1 ) directly or via a manipulation circuit ( 9 ). 6. Arrangement according to claim 1 and 5, characterized in that the sheath ( 3 ) is surrounded by an X-ray absorbing housing ( 7 ) which is placed on a circuit board ( 8 ) which is electrically connected to the security module ( 1 ) . 7. Arrangement according to claim 5, characterized in that the manipulation circuit ( 9 ) is electrically connected to the same only when the security module ( 1 ) is de-energized.