WO2013160032A1

WO2013160032A1 - Method for establishing the originality of a component

Info

Publication number: WO2013160032A1
Application number: PCT/EP2013/055893
Authority: WO
Inventors: Marcel Schumm; Jamshid Shokrollahi
Original assignee: Robert Bosch Gmbh
Priority date: 2012-04-24
Filing date: 2013-03-21
Publication date: 2013-10-31
Also published as: DE102012206726A1

Abstract

In order to determine the originality of a component (1), wherein at least one individual property of the component (1) is used for identifying the originality without the need for exclusive access to secret data, it is proposed that a signature (6) associated with the component (1) be verified using a public key. On the basis of at least one component-specific property of the component (1), a current identifier, that is to say a PUF value, for example, is produced. If the currently produced identifier corresponds to the verified signature (6), the originality of the component (1) is inferred. In this case, the signature (6) corresponds to a code word that is encrypted using a private key, for example a private key from the manufacturer of the component (1).

Description

Description title

Method for determining the originality of a component

State of the art

The invention relates to a method for determining the originality of a component, in particular an electronic component.

The invention further relates to a method for protecting a component against counterfeiting.

The manufacturers of machine components and electronic components are increasingly confronted with the problem that plagiarism of these components are manufactured and distributed unauthorized. In addition to directly measurable sales losses, counterfeits, which usually represent inferior quality counterfeits of the original components, damage the market position or brand image of a company. Such counterfeiting also reduces the reliability of any machinery or equipment in which it is used because there is no assurance that the plagiarism will conform to the technical specifications of the originals. This can be healthful and even

have life-threatening consequences if fake components are used, for example, in the health, automotive or aircraft sector.

To secure components against counterfeiting, it is known to use cryptographic methods and store secret keys in electronic form on the component itself, for example in a suitable memory area of an electronic component or by means of a separate, electronic memory arrangement. The disadvantage here, however, that if this key has been spied by a third party once successful, this electronic Key can also be used on the plagiarism. Whether a present component is an original or a plagiarist can not be determined by means of such cryptographic methods. Increased security in detecting whether the component is an original or a

Plagiarism is and thus an improved copy protection is achieved by a known system in which the security code does not have to be stored on the component itself. Rather, this security code is regenerated each time it is needed using a built-in module on the module. This security code is characteristic of this special component.

The calculation of the component-specific security code takes advantage of the fact that components are never completely identical physically.

For example, in the production process of printed conductors, the smallest variations in thickness and / or length occur. These differences, which do not affect the function of the component, are used to uniquely identify the individual component and make it unique

Generate security code for this component. The security code is usually generated using a measurement circuit that, for example, generates a characteristic clock signal that depends on the exact material composition of the component. Specially designed for this purpose

Electronic circuits read out these measurement data and generate from them the component-specific security key. Such component-specific security key generation systems are so-called physical non-clonable functions (PUUs) integrated into the component.

To ensure the robustness and security of key generation, these systems regularly have error correction in the

Code calculation. To ensure a reliable code generation, even if deviations of the measurement data of the component occur that do not affect the

Material property of the component, but due for example to the current environmental conditions, such as temperature or humidity, the measured values respectively (cryptographic) codes are assigned, the codes are designed such that deviations that do not affect different material properties of the component or the different manufacturing tolerances are due, yet too lead the same code. This is ensured by the fact that the individual code words of the respective code have a sufficiently large distance from one another.

From US Pat. No. 7,681,103 B1, a system is known which is used to protect a component against counterfeiting. In this system, a first value is first generated by means of a PUF. From this value, the code word closest to this PUF value is then determined using so-called "error correcting codes." The difference between this code word and the original PUF value is passed on publicly, whereas the original PUF value is encrypted or kept secret. In order to determine whether an existing component is an original component, a PUF value is generated again and a codeword is formed from this code word, which is then subtracted from the difference value, for example calculated by the manufacturer, only if it is the original component , the resulting value agrees with the

originally formed and secreted PUF value. The

Reliability of this method depends, among other things, on the minimum distance of the selected code.

The disadvantage of this system is that the original PUF value must be kept secret for each component. This means that for each individual manufactured component secret data, for example, in a special

Database, must be filed. Without access to these secret PUF values or the database, the authenticity of a component can not be determined.

Disclosure of the invention

The object of the invention is to provide a method for determining the originality of a component, in which individual properties of the component are used for the recognition of originality, but no exclusive access to secret data is necessary. This task is accomplished by a procedure for determining the originality of a

Component solved by a component assigned to the signature with a public key is verified. Depending on at least one component-specific property of the component, a current identifier is generated, for example from a so-called "PUF" value (physical, nonclonable function, English, "physical unclonable function"). If the currently generated identifier matches an identifier generated to create the signature, the originality of the component is deduced. The signature here corresponds to a codeword that has a private key,

For example, a private key of the manufacturer of the component generated. This signature can be verified by anyone in possession of the public key associated with the private key.

The fact that the signature has been formed with the private key ensures that it has been generated by the owner of the private key. If this signature is now verified with the public key assigned to the private key, the original value (before the

Encrypt with the private key) restored. This can be ensured by the fact that the private key and the associated public key are keys generated with each other.

The signature is preferably generated in that, depending on the at least one component-specific property of the component, a PUF value is generated by means of a PUF and a codeword is then formed from this. This code word represents the identifier. The identifier is now signed with a private key, for example a private key of the manufacturer. Thus, the signature is based on the same code word that is specific to this component. If the code is selected, it is ensured that the same code word is always generated for this component by means of the PUF. Since the signature has been generated by encrypting with the private key, it is ensured that the identifier generated when testing for originality of the component corresponds only to the identifier generated for the creation of the signature, if it is an original component.

In this preferred embodiment of the invention, the signature is a

Addition to the identifier to the original origin of the identifier

sure. It is sufficient if the signature incompletely contains the information contained in the identifier. In a further embodiment of the invention, it is possible to form the signature in that the original identifier is encrypted by means of the private key and thus completely contained in the signature. With a signature formed in this way, it can be sufficient to assign the signature to the component alone, or to at least indirectly connect the signature to the component alone.

An advantage of the method according to the invention is that only a secret key must be present, by means of which in principle all signatures of all components of the manufacturer can be generated. This private key remains with the manufacturer of the component. This spying the key is almost impossible. To determine the originality of a specific component, only the public key that is accessible to everyone is necessary. The signature can be applied to the component itself.

According to an advantageous embodiment of the method, the originally generated identifier from which the signature has been formed, also publicly, for example, together with the component passed. If the identifier and the signature formed therefrom are directly available together with the component, it can be determined immediately whether the signature is a signature generated by an authorized device, in particular the manufacturer, in which it verifies with the public key becomes. Only if this results in the identifier, or if the identifier and the signature correspond to each other, it is an authorized signature. Thus, already in a first step, without the existing mechanisms in the component for generating a current identifier (for example

Activation of the PUF) must be determined whether the component is a forgery. If this test does not indicate a forgery, then the PUF can be used to generate a current identifier and to compare it with the specified data.

Preferably, the signature and / or the identifier are mounted directly on the component. It is particularly advantageous if this is done in machine-readable form, for example as a bar code or as a two-dimensional code. For a machine implementation of the method is favored. However, it is also an alphanumeric form possible.

The object is also achieved by a method for protecting a component from counterfeiting by generating a value dependent on at least one component-specific property of the component by means of a physical, non-clonable function (PUF) and determining an identifier assigned to this value and the Identifier is signed with a private key. The signature thus formed using the identifier is assigned to the component in machine-readable form. Components equipped in this way can be checked for their originality by using the public key and generating a current PUF value or a current identifier, without the need for forwarding secret data.

It is understood that the method is not limited to electronic components. According to the invention, mechanical components can likewise be protected or verified against counterfeiting. For example, variations in machined dimensions of a mechanical component, such as by casting or forging, may be considered "non-clonable" and used in the process.

Further advantageous embodiments of the invention are in the

Subclaims specified. Other features, applications and advantages of the invention will become apparent from the following description of

Embodiments of the invention, which are explained with reference to the drawings, wherein the features both alone and in

different combinations may be important for the invention, without being explicitly referred to again. Show it

Figure 1 is a schematically illustrated component; a flowchart with method steps for the creation of the signature according to a possible embodiment; FIG. 3 is a flowchart of a method for determining the originality of a component according to a possible embodiment; and

FIG. 4 shows a flow chart of the method according to the invention for

Determine the originality of the component according to another

Embodiment.

The method according to the invention is suitable for a large number of different types of components, in particular for machine components and for electronic components. In the embodiment of a component exemplified in FIG. 1, it is designed as an electronic component, for example as an embedded system. The component 1 comprises a housing 2 and a circuit board 3 arranged therein, on which electronic components are arranged. On the board 3, in particular, a component 4 is arranged, by means of which PUF values can be generated. The component 4 includes, for example, in a known manner, a measuring circuit and a ring oscillator, which generates a clock frequency. By activating the component 4, at least one component-specific property is detected by means of the measuring circuit, and a PUF value is generated as a function of this measured value. This PUF value can then be queried, for example by means of a suitable interface. Advantageously, it can be provided that a code word or an identifier is generated in the component 4 from the PUF value, which is then output via suitable interfaces.

On the component 1, a signature 6 and an identifier 7 used for the generation of the signature 6, for example in the form of a sticker 5, are mounted in a region provided for this purpose. In the exemplary embodiment shown in Figure 1, the signature 6 and the

Identification 7 visible in machine-readable form attached as a bar code.

To create the signature 6, first the PUF value, which is generated by means of the component 4, is read. This corresponds to step 101 of the flowchart shown in FIG. In a step 102, a codeword is formed from the PUF value. For this purpose, a suitable code is used, it being ensured that the distance of the individual code words has a size, so that deviations in the measurements in the preparation of the PUF values that are not due to the specific properties of the component 1, but, for example, to instantaneous

Ambient conditions, such as temperature and humidity, yet lead to the same code word or the same identifier 7.

In a step 103, a signature 6, ie, for example, again a string, is formed by encrypting the identifier 7 or a character string corresponding to the identifier 7 or formed from the identifier 7 by encrypting with a private key. In a step 105, this signature 6 is converted into a machine-readable form, for example into a barcode.

Code transferred. Preferably, this signature 6 is applied to the component 1, for example in the form of the sticker 5. Similarly, the identifier generated in step 102 7 or one of these identifier 7 corresponding or formed from this identifier 7 string converted into a machine-readable code and also on the Component 1 are readably attached.

FIG. 3 shows a possible realization of the method according to the invention in the form of a flowchart. In a step 201, a current PUF value is determined by a suitable activation of the function group 4. In a step 202, a code word or a current identifier analogous to the method step described in FIG. 2 in step 102 is created from this PUF value. In a step 203, the component 6 associated with the component 1 and, for example, in the form of a label or sticker 5 on the component 1 attached signature 6 and the identifier 7 are read. This is preferably done by mechanical help, for example by means of a suitable scanner. In a step 204, the signature 6 is verified by means of the public key. Since the public key to the private key with which the signature 6 has been formed is symmetrical, or the two keys have been generated with each other, an original one must be used

Component 1, the identified in step 204 by verifying the signature 6 or verified identifier 7 with the current identifier formed in step 202. This match is checked in step 205. Only if there is a match is it concluded that the component 1 is original in step 206. Otherwise, in a step 207, the originality is denied. As is clear from the embodiment shown in Figure 3, is for checking a component 1 on originality with the invention

Procedure no exchange of secret signatures, identifiers or cryptographic keys required. The private key, with the help of which the signature 6 is generated, remains with the creator of the signature 6,

For example, the manufacturer of the component. 1 Only the public key must be available for validation or verification. Characterized in that the originally generated identifier 7 (step 102) has been encrypted with the private key, so that the signature 6 has been clearly formed from the original identifier 7 of the component 1, a falsification of this component 1 can be easily recognized. If the component 1 were to be changed or if the component 1 were a forgery, then the determination of the current identifier (steps 201 and 202), which takes place during the checking of the originality of the component 1, would no longer be identical to the original one Identification 7. A forgery of the signature 6, for example, by replacing the sticker 5, is not possible because the signature 6 is valid only if it is with the private

Key that belongs to the public key has been encrypted.

Otherwise, also here in step 205, the values determined in steps 202 and 204 would not match.

The method according to the invention offers the possibility of also applying the identification 7 to the component 1. This allows further tests. So can the

Correctness of the signature 6 and the identifier 7 are checked by verifying the signature 6 with the public key (of the manufacturer), whereby the identifier 7 originally used for generating the signature 6 is formed or verified. Only if the value thus obtained agrees with the identifier 7 or corresponds to the identifier 7 (that is, matches the identifier 7), are the specifications (signature 6 and identifier 7) validated. Thus, if a counterfeiter produced a counterfeit component 1 and attached the identifier of this counterfeit component 1 to the component 1, then this counterfeit identifier 7 would in any case not agree with the signature verified with the public key 6 or would not fit. FIG. 4 shows a flowchart of a further possible embodiment of the method according to the invention. The method begins in a step 301, in which first the PUF value is determined. In a step 302, the codeword or a current identifier is determined from the determined current PUF value. In a step 303, the identifier 7 attached to the component 1 is read. In a step 304, the identifier 7 read in the step 303 is compared with the currently generated identifier (step 302). If these identifiers do not match, the component 1 is qualified as a counterfeit and branches to step 308. The two agree

However, if identifiers match, the signature 6 is read in a step 305 and by verifying the signature 6 with the public key (of the manufacturer) the original identifier is reconstructed or the identifier 7 attached to the component 1 is verified. In a step 306, the original identifier is compared with the current identifier formed in step 302. If these identifiers match, or if the identifier 7 affixed to the component 1 has been verified by means of the signature 6 as originating from the manufacturer, the originality of the component 1 is concluded in the step 307, otherwise the program branches to the step 308 and the originality of the Component 1 is not recognized.

Claims

claims

1 . Method for determining the originality of a preferably

electronic component (1), characterized in that the component (1) associated with using a function of at least one component-specific property of the component (1) generated identifier (7) by means of a private key formed signature (6) is verified to a private key associated with the public key, that in dependence on the at least one component-specific property of the component (1) a current identifier is generated, and that the originality of the component (1) is closed, if the current identifier with the identifier used for creating the signature (6) (7) matches.

2. The method according to claim 1, characterized in that for the

Creation of the signature (6) generated identifier (7) and / or the current identifier by means of a physical, non-clonable function is generated by the component (1) assigned or in the component (1) integrated component (4) is activated in that the component (4) measures at least one component-specific property by means of a measuring circuit and the identifier (7) is generated as a function of the at least one measured value.

3. The method according to any one of the preceding claims, characterized

in that the signature (6) is connected in machine-readable form at least indirectly to the component (1).

4. The method according to any one of the preceding claims, characterized

in that the identifier (7) generated for the creation of the signature (6) is connected in machine-readable form at least indirectly to the component (1). Method according to one of the preceding claims, characterized

in that, in order to determine the originality of the component (1), the signature (6) is verified with the public key using the identifier (7) generated for the creation of the signature (6) and an originality is denied, if the signature ( 6) does not correspond to the identifier (7) generated for the creation of the signature (6).

Method according to one of the preceding claims, characterized

in that, for the determination of the originality of the component (1), the identifier currently generated is compared with the identifier (7) generated for the creation of the signature (6) and an originality is denied if the identifier currently generated does not match that for the Creation of the signature (6) generated identifier (7) matches.

Method according to one of the preceding claims, characterized

characterized in that the physical non-clonable function is formed using a ring oscillator.

Method for protecting a component (1) against counterfeiting, characterized

in that a value dependent on at least one component-specific property of the component (1) is generated by means of a physical, non-cloneable function, that an identifier (7) assigned to this value is determined, and that the identifier (7) is used. a signature (6) is formed by means of a private key, and that the identifier (7) and / or the signature (6) in alphanumeric form and / or in machine-readable form is assigned to the component (1).

A method according to claim 8, characterized in that the identifier (7) generated for the creation of the signature (6) is generated by means of a physical non-clonable function in that one of the component (1) associated or in the component (1) integrated Component (4) is activated, the component (4) by means of a measuring circuit measures at least one component-specific property and in dependence on the at least one measured value, the identifier (7) is generated.