DE102019213666B4 - Authentication procedure for data - Google Patents

Abstract

Authentication method for data that is transmitted from a first control device to a second control device, the control devices each being connected to an identical voltage source, with the following steps: Supplying the first control device and the second control device with voltage that is subject to stochastic processes by means of the Voltage source; Digitizing the voltage; Generating a first stamp on the basis of the stochastic voltage profile of the digitized voltage by means of the first control device and generating a second stamp on the basis of the stochastic voltage profile of the digitized voltage by means of the second control device; Transmission of data and transmission of the first stamp and / or the second stamp from the first control device to an evaluation device; Authentication of the data by means of the second control device when at least one most significant bit sequence of the stamp transmitted by the first control device is identical to at least one most significant bit sequence of the stamp generated by the second control device.

Description

FIELD OF THE INVENTION

The present invention relates to an authentication method for data and a control unit module for a vehicle with at least two control units.

TECHNICAL BACKGROUND

In the context of autonomous driving, it is known to control vehicles using at least two control devices.

the EP 3 550 461 A1 suggests authenticating devices based on a current strength curve.

the EP 2 571 131 B1 suggests using a communication protocol to authenticate a battery.

SUMMARY OF THE INVENTION

Against this background, the invention is based on the object of ensuring a secure exchange of data between several control devices.

According to the invention, this object is achieved by an authentication method for data with the features of claim 1 and / or by a control unit module for a vehicle with the features of claim 6.

Vehicles within the meaning of this patent application are land vehicles, aircraft and / or watercraft.

In this patent application, the authentication of data is understood to mean that the authenticity of data is checked.

Identical means that something is the same.

A control device is, for example, an ECU. Control devices are electronic modules that are used for control or regulation.

A voltage source is, for example, a battery.

Stochastic processes are not deterministic and are subject to a random process. For example, a noise process is subject to a stochastic process.

In this patent application, a stamp is understood to be a data word for authenticating data.

The bit value defines the value of a bit that it should have due to its position within a binary number. The so-called least significant bit is the bit with the lowest bit value in a data word. The opposite of least significant bit is most significant bit. It designates the bit with the highest bit value 1 bit in a data word.

A least or most significant bit sequence is a bit sequence that begins or ends with a least or most significant bit.

The underlying idea of the invention is to connect at least two control devices to an identical voltage source that is subject to a stochastic voltage curve. A stochastic voltage curve can be provided by means of a conventional vehicle battery, since the on-board network voltage of a vehicle is subject to stochastic processes due to non-deterministic effects. However, since the stochastic voltage curve is only known to consumers who are also connected to the corresponding voltage source, the invention provides for a stamp to be generated to authenticate the control devices in a data connection on the basis of the stochastic voltage curve.

Accordingly, the first stamp and the second stamp are transmitted to an evaluation unit, which compares the stamps. It goes without saying that the evaluation unit can also be designed as a sub-unit of one of the control devices, e.g. the first control device. In this case, it is sufficient to transmit the second stamp to the sub-unit of the first control device (evaluation unit). The first stamp is transmitted internally to the sub-unit (evaluation unit) by the first control unit.

Advantageous refinements and developments emerge from the further subclaims and from the description with reference to the figures of the drawing.

According to a preferred development of the invention, the voltage is decoupled from a DC voltage.

According to a preferred development of the invention, a least significant bit sequence of the stamp is discarded or masked. This makes it possible to provide a fault tolerance option for the voltage transmission, for example due to noise or other disruptive factors. For example, it is conceivable that, particularly when the control units are arranged at a distance from one another, the voltage in a line to the control units is in each case exposed to different interference factors. If one assumes that such disruptive factors only has a minor effect on the voltage signal that arrives at a control device, it is advantageous to discard or mask a least significant bit sequence of the stamp.

According to a preferred development of the invention, the stamp has a time stamp. In this way, the authentication of the transmitted data can be linked or clearly assigned to a point in time of the stochastic voltage signal.

According to a preferred development of the invention, the transmitted data are identified. For example, it is conceivable to monitor incoming paths into a control device, each incoming path being assigned a signature. A manipulation attempt can thus be detected from the outside.

The method according to the invention for authenticating data or the control device module for a vehicle is particularly suitable for vehicles with several control devices. These are, for example, trucks with a first control device for a driven part of the truck and with a second control device for a trailer of the truck.

Figure list

• 1 eine Prinzipskizze gemäß einer Ausführungsform der Erfindung;
• 2 ein schematisches Blockdiagramm einer Ausführungsform der Erfindung;
• 3 ein schematisches Blockdiagramm einer Ausführungsform der Erfindung.

The present invention is explained in more detail below with reference to the exemplary embodiments specified in the schematic figures of the drawings. It shows:

• 1 a schematic diagram according to an embodiment of the invention;
• 2 a schematic block diagram of an embodiment of the invention;
• 3 a schematic block diagram of an embodiment of the invention.

The accompanying drawings are intended to provide a further understanding of the embodiments of the invention. They illustrate embodiments and, in conjunction with the description, serve to explain principles and concepts of the invention. Other embodiments and many of the advantages mentioned emerge with a view to the drawings. The elements of the drawings are not necessarily shown to scale with one another.

In the figures of the drawings, elements, features and components that are the same, functionally identical and have the same effect - unless stated otherwise - are each provided with the same reference symbols.

DESCRIPTION OF EXEMPLARY EMBODIMENTS

1 shows a schematic principle diagram for an authentication method for data. It can be seen that a voltage source 16 , in the 1 is designed as a battery, a voltage with a stochastic voltage curve 18th provides. The next step is the stochastic voltage curve 18th decoupled from a DC voltage. In a next step, the decoupled voltage signal 101 digitized. The next step is the digitized voltage signal 103 a stamp 20th generated.

2 shows a schematic block diagram according to an embodiment of a method for authenticating data. In the step S1 becomes a first and a second control unit 12th , 14th by means of a voltage source 16 provided. In the step S2 is the voltage by means of the first and second control device 12th , 14th digitized. In the step S3 becomes a stamp 20th due to the stochastic voltage curve 18th by means of the first and second control device 12th , 14th generated. In the step S4 become dates and the stamp 20th from the first control unit 12th to the second control unit 14th transmitted. In the step S5 are data by means of the second control unit 14th authenticated if at least one most significant bit sequence of the transmitted stamp 20th with at least one most significant bit sequence from the second control unit 14th generated stamp 20th is identical.

3 shows a schematic block diagram according to an embodiment of a control device module 10 . The control unit module 10 comprises a first control device 12th and a second control unit 14th . The control units 14th , 16 are with a voltage source 16 connected to the control units 12th , 14th by means of electrical conductors 107 supplied with voltage. Between the control units 12th , 14th there is a data connection 105 to exchange control commands. In order to check the authenticity of the transmitted control commands, the control command data are checked using the method according to 2 authenticated.

List of reference symbols

10

Control unit module

12th

Control unit

14th

Control unit

16

Voltage source

18th

Stress curve

20th

rubber stamp

101

decoupled voltage signal

103

digitized voltage signal

105

Data Connection

107

electrical conductor

S1-S5

Procedural steps

Claims (6)

Authentication method for data which is transmitted from a first control device (12) to a second control device (14), the control devices (12, 14) each being connected to an identical voltage source (16), with the following steps: - Supplying (S1) the first control device (12) and the second control device (14) with voltage, which is subject to a stochastic process, by means of the voltage source (16); - digitizing (S2) the voltage; - Generating (S3.1) a first stamp (20) based on the stochastic voltage profile of the digitized voltage by means of the first control device (12) and generating (S3.2) a second stamp (20) based on the stochastic voltage profile of the digitized voltage by means of the second Control device (14); - Transmission (S4) of data and transmission of the first stamp (20) from the first control device (12) to an evaluation device; - Authentication (S5) of the data by means of the evaluation device when at least one most significant bit sequence of the first stamp (20) is identical to at least one most significant bit sequence of the second stamp (20). Authentication procedure for data according to Claim 1 , wherein the voltage is decoupled from a DC voltage by means of the first and second control device (12, 14). Authentication method for data according to one of the preceding claims, wherein a least significant bit sequence of the stamp (20) is discarded and / or masked. Authentication method for data according to one of the preceding claims, wherein the stamp (20) has a time stamp. Authentication method for data according to one of the preceding claims, wherein an origin of the transmitted data is determined. Control device module (10) for a vehicle with a first control device (12), a second control device (14) and a voltage source (16) for supplying the first control device (12) and the second control device (14) with voltage, the first and the second control device (12,14) are set up, the method according to Claim 1 perform.

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