DE102020205657A1 - Method and device for managing data - Google Patents

Abstract

The invention relates to a method for managing data (D). The method has a step of encrypting collected data (D) with a first cryptographic key (t) in order to generate encrypted data (K). The first key (t) is a key generated specifically for the collected data (D). The method also has a step of combining the first key (t) with a second cryptographic key (p) to generate an encrypted first key (t ') and the encrypted first key (t') with metadata (X) to create a packet (T). The metadata (X) have time information for the data (D) that is valid for the data (D). The method also has a step of appending a cryptographic signature to the packet (T).

Description

State of the art

The invention is based on a device or a method according to the preamble of the independent claims. The present invention also relates to a computer program.

In vehicles in particular, confidential data can also arise, for example. For example, statutory storage periods may apply to such data. In an attack scenario, for example, the wrong time can be played.

Disclosure of the invention

Against this background, with the approach presented here, a method, furthermore a device which uses this method, and finally a corresponding computer program according to the main claims are presented. The measures listed in the dependent claims make advantageous developments and improvements of the device specified in the independent claim possible.

According to embodiments, in particular time-limited access to data, in particular vehicle data, can be implemented in that an encryption of the data can be used to determine an expiry date of time information, for example a storage period, for this data, with a separate key being generated for the data Provided metadata and this extended key can then be used to decrypt or recognize the expiry date of time information for the data.

According to embodiments, data in particular can advantageously be encrypted, in particular in a vehicle, in such a way that administration or management of access rights is made possible. This ensures that the data can only be used for a certain period of time or for defined purposes. This means that deletion periods can be adhered to even after the data has been transferred from the vehicle. A possible attack scenario on the availability of the data can be prevented in which an integrated deletion function, for example in a vehicle, is started too early by playing a wrong time, in particular a future time, and as a result legal storage periods are not adhered to. In this way, a time-driven extinguishing function, for example in a vehicle, can be saved.

• Verschlüsseln von erhobenen Daten mit einem ersten kryptografischen Schlüssel, um verschlüsselte Daten zu erzeugen, wobei der erste Schlüssel ein spezifisch für die erhobenen Daten erzeugter Schlüssel ist;
• Kombinieren des ersten Schlüssels mit einem zweiten kryptografischen Schlüssel, um einen verschlüsselten ersten Schlüssel zu erzeugen, und des verschlüsselten ersten Schlüssels mit Metadaten, um ein Paket zu erzeugen, wobei die Metadaten eine für die Daten gültige Zeitinformation für die Daten aufweisen; und
• Anhängen einer kryptografischen Signatur an das Paket.

A method for managing data is presented, the method comprising the following steps:

• Encrypting collected data with a first cryptographic key to generate encrypted data, the first key being a key generated specifically for the collected data;
• Combining the first key with a second cryptographic key to generate an encrypted first key and the encrypted first key with metadata to generate a packet, the metadata including time information valid for the data for the data; and
• Attaching a cryptographic signature to the package.

This method can be implemented, for example, in software or hardware or in a mixed form of software and hardware, for example in a control device or a device. At least a subset of the steps of the method can be executed in a control unit or a device of a vehicle. The confidential data can originate from a facility of a vehicle. The data collected can be personal data or other data classified as confidential based on a predefined criterion. The predefined criterion can be a legal requirement, a user preference or the like. The vehicle can be a motor vehicle, for example a passenger car or a commercial vehicle. The first key can be a key generated specifically for the confidential data collected. The metadata can have at least one piece of assignment information that enables an assignment between the encrypted data and the packet. The metadata can have the valid time information as validity information, which represents a storage period, a deletion period and additionally or alternatively a time stamp of a generation. The metadata, more precisely the validity information or time information, can have or represent a storage period and additionally or alternatively an expiration date of the first cryptographic key. Additionally or alternatively, the metadata or the validity information or time information can have or represent a time stamp of a point in time at which the data was collected or generated. An expiration date can be calculated from the time stamp. In other words, in the combining step, the first key can be encrypted with the second key. In the appending step, the package can be signed with the signature. The method can also include a step of reading in the data collected from a Have an interface to a data source, in particular a data source of the vehicle. The method can furthermore have a step of generating the first key and additionally or alternatively the metadata. The encrypted data and the package can be provided in a step of providing for output to an interface to a data transmission device and additionally or alternatively to a storage device.

According to one embodiment, metadata can be used in the combining step that is unencrypted or encrypted and is additionally or alternatively provided with a cryptographic signature. Additionally or alternatively, unencrypted or encrypted metadata with an additional or alternative cryptographic signature can be added to the encrypted data in the encryption step. Such an embodiment offers the advantage that suitable variants can be provided for different application scenarios.

In the case of a change in the time information that is subsequently determined, the step of combining can also be carried out again in order to combine further metadata with the encrypted first key or with the packet in order to generate a further packet. In this case, the further metadata can have time information that has changed compared to the time information. The further package can also be signed. The package can also be referred to as the original package. The further metadata can have a hash value for identifying the original packet. In addition, in the checking step, the further metadata from the further package can be checked for an expiry of the changed time information. Such an embodiment offers the advantage that, for example, the storage period can be extended in an uncomplicated and secure manner.

Furthermore, according to one embodiment of the approach presented here, a method for evaluating data is presented, the method having a step of reading in a packet that was created using a method according to a variant of the approach presented here and to which a cryptographic signature was appended. The method further comprises a step of checking the metadata from the packet for an expiration of the time information in order to generate a check result which indicates whether the time information has expired or is still running. In addition, in the checking step, the signature with which the package is signed can also be checked for correctness. Such an embodiment offers the advantage that it can be checked in a simple and secure manner whether the data remain stored or can be deleted.

Furthermore, the method can have a step of decrypting the encrypted first key from the packet with a third cryptographic key. The third key can correspond to the second key. The method can also have a step of generating decrypted data from the encrypted data by means of the decrypted first key from the packet. In this case, the step of decrypting and additionally or alternatively the step of generating can be carried out as a function of the test result. More precisely, the step of decrypting and additionally or alternatively the step of generating can be carried out if the test result generated in the step of checking indicates that the storage period is still running. In the generation step, the encrypted data can be decrypted from the packet using the decrypted first key in order to generate decrypted data. Such an embodiment offers the advantage that confidential handling of the data is made possible in a reliable manner.

In addition, the method can have a step of performing a transformation and additionally or alternatively filtering the decrypted data in order to anonymize the decrypted data and additionally or alternatively transform it into a format prescribed for the data. Such an embodiment offers the advantage that special regulations applicable to data can be implemented easily and safely.

The step of decrypting can be carried out in a trustworthy environment or the step of decrypting and the step of checking, the step of generating and additionally or alternatively the step of performing can be carried out in a trustworthy environment. The trustworthy environment can be outside of the access of those involved and can be made available by an independent body or authority. In particular, the third key can only be present within the trustworthy one. Such an embodiment offers the advantage that, depending on the application, at least the decryption step can be carried out in a trustworthy environment in order to meet specific security requirements.

• - die Schritte des Verfahrens zum Verwalten von Daten; und
• - die Schritte des Verfahrens zum Bewerten von Daten.

Furthermore, according to a further embodiment, a method for processing data is presented, the method having the following steps:

• - the steps of the method for managing data; and
• - the steps of the method for scoring data.

Such an embodiment also enables the advantages of the approach presented here to be implemented particularly efficiently and quickly.

The approach presented here also creates a device which is designed to carry out, control or implement the steps of a variant of a method presented here in corresponding devices. The object on which the invention is based can also be achieved quickly and efficiently by means of this embodiment variant of the invention in the form of a device.

For this purpose, the device can have at least one processing unit for processing signals or data, at least one storage unit for storing signals or data, at least one interface to a sensor or an actuator for reading in sensor signals from the sensor or for outputting data or control signals to the Have actuator and / or at least one communication interface for reading in or outputting data, which are embedded in a communication protocol. The computing unit can be, for example, a signal processor, a microcontroller or the like, wherein the storage unit can be a flash memory, an EEPROM or a magnetic storage unit. The communication interface can be designed to read in or output data wirelessly and / or wired, a communication interface that can read in or output wired data, for example, can read this data electrically or optically from a corresponding data transmission line or output it into a corresponding data transmission line.

In the present case, a device can be understood to mean an electrical device that processes sensor signals and outputs control and / or data signals as a function thereof. The device can have an interface which can be designed in terms of hardware and / or software. In the case of a hardware design, the interfaces can, for example, be part of a so-called system ASIC which contains a wide variety of functions of the device. However, it is also possible that the interfaces are separate, integrated circuits or at least partially consist of discrete components. In the case of a software-based design, the interfaces can be software modules that are present, for example, on a microcontroller alongside other software modules.

A computer program product or computer program with program code, which can be stored on a machine-readable carrier or storage medium such as a semiconductor memory, a hard disk memory or an optical memory, and for carrying out, implementing and / or controlling the steps of the method according to one of the embodiments described above is also advantageous is used, especially when the program product or program is executed on a computer or device.

• 1 eine schematische Darstellung eines Fahrzeugs mit einer Vorrichtung gemäß einem Ausführungsbeispiel;
• 2 ein Ablaufdiagramm eines Verfahrens zum Verwalten gemäß einem Ausführungsbeispiel;
• 3 eine schematische Darstellung eines Teils einer Vorrichtung gemäß einem Ausführungsbeispiel;
• 4 eine schematische Darstellung eines Pakets gemäß einem Ausführungsbeispiel; und
• 5 eine schematische Darstellung eines Teils einer Vorrichtung gemäß einem Ausführungsbeispiel.

Embodiments of the approach presented here are shown in the drawings and explained in more detail in the description below. It shows:

• 1 a schematic representation of a vehicle with a device according to an embodiment;
• 2 a flowchart of a method for management according to an embodiment;
• 3 a schematic representation of part of a device according to an embodiment;
• 4th a schematic representation of a package according to an embodiment; and
• 5 a schematic representation of part of a device according to an embodiment.

In the following description of advantageous exemplary embodiments of the present invention, identical or similar reference numerals are used for the elements shown in the various figures and having a similar effect, a repeated description of these elements being dispensed with.

1 shows a schematic representation of a vehicle 100 with a device 110 to manage data D. according to an embodiment. According to another embodiment, the device 110 can also be implemented in an environment other than a vehicle. With the vehicle 100 it is a motor vehicle, for example a land vehicle, in particular a passenger car, a truck or another utility vehicle.

From the vehicle 100 are in the representation of 1 in addition to the device 110 for example only one data source 102 , a first vehicle device 104 and a second vehicle device 106 shown. The first in-vehicle equipment 104 and the second vehicle device 106 are according to the one shown here Embodiment arranged physically separated from one another and connected to one another capable of data transmission. The device 110 assign facilities 122 , 124 , 126 , 132 , 134 , 136 , 138 on, of which a first subset in the first vehicle device 104 is arranged and a second subset of the second vehicle device 106 is arranged. The one in the second vehicle equipment 106 arranged facilities 132 , 134 , 136 , 138 the device 110 are implemented in a trustworthy environment according to the exemplary embodiment shown here. On the facilities 122 , 124 , 126 , 132 , 134 , 136 , 138 the device 110 will also be discussed in greater detail with reference to the following figures.

The device 110 is to manage the data D. trained to handle collected data D. from an input interface 112 the data source 102 read in, process for administration and in decrypted form or as filtered or transformed data D ' to an output interface 114 ready for output. Between those in the first vehicle equipment 104 arranged facilities 122 , 124 , 126 the device 110 and that in the second vehicle device 106 arranged facilities 132 , 134 , 136 , 138 the device 110 can based on the data D. generated encrypted data K as well as a package T or key packet are transmitted.

The device 110 has an encryption facility 122 , a combination device 124 and a hitch 126 on. The encryption facility 122 , the combination device 124 and the hitch 126 are in the first vehicle device according to the exemplary embodiment shown here 104 arranged. The encryption facility 122 is trained to use the collected data D. with a first cryptographic key to generate encrypted data. The first key is specific to the data collected D. generated key. The combination device 124 is configured to combine the first key with a second cryptographic key to generate an encrypted first key, and to combine the encrypted first key with metadata to generate a packet or unsigned packet. The metadata has a time information for the data D. valid retention period for the data D. on. The towing device 126 is designed to attach a cryptographic signature to the package or unsigned package to the package T or to generate a signed package.

The device 110 According to one exemplary embodiment, furthermore has a test device 132 , a decryption device 134 , a generating device 136 and an implementation device 138 on. The test facility 132 , the decryption facility 134 , the generating facility 136 and the implementation facility 138 are in the second vehicle device according to the exemplary embodiment shown here 106 arranged. The test facility 132 is trained to take the metadata from the package T to check for an expiry of the storage period in order to generate a test result. The test result generated in this way shows whether the storage period has expired or is still running. The decryption device is activated as a function of the test result 134 , the generating facility 136 and optionally the implementation device 138 . In particular, if the test result indicates that the storage period is still running, the decryption device is activated 134 , the generating facility 136 and optionally the implementation device 138 .

The decryption facility 134 is designed to take the encrypted first key from the package T to decrypt with a third cryptographic key. The generating facility 136 is designed to use the decrypted first key from the package T from the encrypted data K decrypted data D. to create. In other words, the generating device is 136 trained to use the encrypted data K with the decrypted first key from the package T to decrypt to decrypted data D. to create. According to one embodiment, the implementation device is 138 designed to transform and / or filter the decrypted data D. perform to the decrypted data D. to anonymize and / or to transform into a prescribed format for the data, in other words to the filtered or transformed data D ' to generate.

2 shows a flow chart of a method 200 to manage data and a subsequent procedure 235 for evaluating data according to an embodiment. The procedure 200 to manage data and the procedure 235 for evaluating data can be carried out on the same unit or on different, for example spatially separate units. Furthermore, the steps of the method 200 to manage data and the procedure 235 for evaluating data one at a time in either of the two methods 200 and 235 compound procedures 280 to process data.

The procedure 200 is using the device off 1 or a similar device executable. The data come from a vehicle, for example, such as the vehicle from 1 . In particular, the procedure 200 at least partially executable in a vehicle, such as the vehicle from 1 .

In one step 210 of encryption are part of the process 200 initially collected data is encrypted with a first cryptographic key in order to generate encrypted data. The first key is a key generated specifically for the data collected. Below is in one step 220 of combining the first key with a second cryptographic key to produce an encrypted first key, and combining the encrypted first key with metadata to produce a packet. According to one embodiment, in step 220 of combining uses metadata that is unencrypted or encrypted and / or is provided with a cryptographic signature. The metadata has a valid retention period for the data. Below is in one step 230 after appending, a cryptographic signature is appended to the packet generated in this way.

According to one embodiment, in the method 235 to evaluate data initially in one step 237 of reading in the one package that is read in with one with a process 200 according to a variant of the approach of a method presented here 200 to manage data and to which a cryptographic signature has been attached. Furthermore takes place in the procedure 235 for evaluating data subsequently in one step 240 of checking, the metadata from the package is checked for an expiration of the storage period in order to generate a test result which indicates whether the storage period has expired or is still running. According to an exemplary embodiment, a step is subsequently carried out as a function of the test result 250 of decryption and one step 260 of creation. In the step 250 After decryption, the encrypted first key from the packet is decrypted with a third cryptographic key. The following are in the step 260 after generating by means of the decrypted first key from the packet from the encrypted data then decrypted data is generated. Optionally in addition, the method 200 next one step 270 performing a transformation and / or filtering the decrypted data in order to anonymize the decrypted data and / or to transform it into a format prescribed for the data. According to one embodiment, the step 240 of decryption is carried out in a trustworthy environment. According to another embodiment, both the step 240 of decryption as well as the step 250 of testing, the step 260 of generating and / or the step 270 of performing in a trusted environment.

According to one embodiment, the step 220 of combining is carried out again if a change in the storage period is subsequently determined. Thereby the step 220 of combining is carried out again in order to combine further metadata with the encrypted first key or with the packet in order to generate a further packet. The other metadata have a different storage period than the storage period. The further package or the further metadata is used in the subsequent steps of the procedure.

3 shows a schematic representation of part of an apparatus 110 to manage data D. according to an embodiment. The in 3 Part of the device shown 110 corresponds to or is similar to the part of in 1 shown device, which is arranged in the first vehicle device. In addition to the device 110 are in the representation of 3 also a trigger 301 and a data recorder as a data source 102 drawn. From the data source 102 will be the data D. responsive to the trigger 101 provided or by the device 110 read in.

From the device 110 are also a key generation device according to the embodiment shown here 116 and a metadata generator 118 shown. The key generator 116 is designed to be responsive to the trigger 301 the first key t to create. The metadata generator 118 is designed to be responsive to the trigger 301 the metadata X to create.

The encryption facility 122 is trained to view the data D. with the first key t to encrypt to the encrypted data K to create. The combination device 124 is trained to use the first key t combine with the second key p to generate an encrypted first key and the encrypted first key with the metadata X to combine to make the package T to generate or first of all to generate an unsigned package to which the signature is appended, in order to finally create the package T to obtain. In 3 however, is the pending establishment of the device 110 for the sake of clarity omitted in the illustration. In addition, with reference to 4th even more detailed on the package T received.

4th shows a schematic representation of a package T according to an embodiment. With the package T it is the package from one of the figures described above. 4th In other words, shows a schematic structure of the package T . The package T assigns the encrypted first key t ' and the metadata X on, those related to the unsigned package T ' are combined. The unsigned package T ' results together with the signature S. the package T or signed package.

5 shows a schematic representation of part of an apparatus 110 to manage data D. according to an embodiment. The in 3 Part of the device shown 110 corresponds to or is similar to the part of in 1 shown device, which is arranged in the second vehicle device. In 5 is also a trustworthy environment 506 shown, which is, for example, part of the second vehicle equipment. The test facility 132 , the decryption facility 134 , the generating facility 136 and the implementation facility 138 are in the trustworthy environment according to the exemplary embodiment shown here 506 realized.

In the representation of 5 are the test facility 132 and the decryption device 134 summarized in a schematic block. The test facility 132 is trained to take the package T to recieve. The decryption facility 134 is designed to handle the one in the package T contained, encrypted first key by means of the third key q to decipher. The third key q is only in the trustworthy environment 506 before. The first key that has been decrypted again t and the metadata X are an output of the testing facility 132 and the decryption device 134 on pointing blocks. The generating facility 136 generated from the encrypted data K using the decrypted first key t again the data D. in decoded form. The implementing body 138 carries out further processing of the data D. optionally also using the metadata X through to the filtered and / or transformed data D ' to generate.

With reference to the figures described above, exemplary embodiments are again summarized and briefly explained in other words.

There are a pair of cryptographic keys, the second key p and the third key q . The second key p is used exclusively for encryption and the third key q is only used for decryption. The second key can p and the third key q be equal.

When in the vehicle 100 data D. will be collected, a new first key t generated. The data collected D. be with the first key t encrypted and as encrypted data K designated. Additionally or alternatively, the first key t and the encrypted data K when reading out the data D. generated. The first key t gets itself with metadata X , such as an expiration date, provided and encrypted with the second key p and then as an unsigned packet T ' designated. In the unsigned package T ' is the first key t contain encrypted metadata X themselves are available unencrypted. It will be a package T generated by sending the unsigned packet T ' a cryptographically secure signature S. about all contents of the unsigned package T ' is appended. The signature S. for the unsigned package T ' can with the key pair, the second key p and the third key q , or a second or different key pair (p ', q').

Optionally, the package T and / or the encrypted data K with encrypted or unencrypted and / or signed metadata X be or will be provided. The metadata X contain at least all the information that is necessary for the package T the encrypted data K assign, and an expiration date of the first key t . In addition or as an alternative to the expiry date, a time stamp of the time of data generation can also be included in the metadata X which is used to calculate an expiration date.

To the data D. from the encrypted data K The first thing to get is the validity of the package T checked. To do this, the signature S. and checked the expiration date or timestamp. This check takes place in the trustworthy environment 506 . The third key q lies only within this trustworthy environment 506 before.

When the validity of the package T is established, the first key can t by decryption with the third key q be generated. Then the data can D. by decryption from the encrypted data K with the first key t be generated. Optionally, a time-dependent or user-dependent transformation of the data can be used to further safeguard data protection D. take place. Such a transformation can, for example, anonymize the data D. or the removal of critical data or the transfer of the data D. in a certain format, which itself also has protective mechanisms. It is also possible to convert it into a format that is prescribed by, for example, approval authorities in certain countries.

In a less restrictive variant, you can only decrypt the package T in the trusted environment 506 and it can be the first key t be returned. If there is a communication with the trustworthy environment 506 itself is not trustworthy, communication takes place with the trustworthy environment 506 through communication provided with additional protective measures. The trustworthy environment 506 can be outside the access of those involved and be or will be made available by an independent body.

Will be in the device 110 , in which the encrypted data K are generated, after their generation a reason is recognized that a longer storage period for the data D. allowed or required, and the package T has already been generated, a new set of metadata M 'is generated which contains the new storage duration due to a later expiry date. If no expiration date but a time stamp is stored, the extended storage period is encoded by another date, such as an event severity. The new set of metadata M 'additionally contains a hash value, for example an SHA-3 hash value or a hash value created by means of another secure hash method, of the package T whose period of validity is to be extended. The new set of metadata M 'is analogous to the unsigned packet T ' , set up and signed and another package M is generated. To check the validity of the package T the further package M is also used if the package T is no longer valid.

Alternatively, the further metadata M 'and the packet T used, the package T Encrypted is present in the further packet M, analogous to the first key t in the package T . The further package M is thus complete and the package T is no longer required. The metadata in the new set of metadata M 'can be encrypted or in the form of plain text. The authenticity of the unencrypted metadata is ensured in the further package M by means of a signature.

The procedure for extending the storage period can be linked in all given variants in order to extend the storage period several times. To determine the validity of the package T all further packages M, which define an extension, are required. In the alternative variant, this is implicitly the case when the last further package M is present.

Checking the validity of the package T can instead of the package T alone use all verified metadata of the further packet M in order to allow the extension of the storage period.

If an exemplary embodiment comprises an “and / or” link between a first feature and a second feature, this is to be read in such a way that the exemplary embodiment according to one embodiment has both the first feature and the second feature and, according to a further embodiment, either only the has the first feature or only the second feature.

Claims (11)

Method (200) for managing data (D), the (200) method comprising the following steps: Encrypting (210) collected data (D) with a first cryptographic key (t) in order to generate encrypted data (K); Combining (220) the first key (t) with a second cryptographic key (p) to generate an encrypted first key (t ') and the encrypted first key (t') with metadata (X) to generate a packet ( T), the metadata (X) having time information for the data (D) that is valid for the data (D); and Appending (230) a cryptographic signature (S) to the packet (T). Method (200) according to Claim 1 wherein in the step (220) of combining metadata (X) are used which are unencrypted or encrypted and / or are provided with a cryptographic signature (S). Method (200) according to one of the preceding claims, wherein in the case of a subsequently determined change in the time information, the step (220) of combining is carried out again in order to add further metadata with the encrypted first key (t ') or with the packet (T) combine in order to generate a further packet, the further metadata having time information that has been changed in relation to the time information. Method (235) for evaluating data (D), the method (235) having a step (237) of reading in a packet (T) which is processed with a method (200) according to one of the preceding Claims 1 until 3 and to which a cryptographic signature (S) has been appended, the method (235) further comprising a step (240) of checking the metadata (X) from the packet for an expiration of the time information in order to generate a checking result which shows whether the time information has expired or is still running. Method (235) according to Claim 4 , with a step (250) of decrypting the encrypted first key (t ') from the packet (T) with a third cryptographic key (q) and with a step (260) of generating decrypted data (D) from the encrypted data ( K) by means of the decrypted first key (t) from the packet (T), the step (250) of decrypting and / or the step (260) of generating being or being carried out as a function of the test result. Method (235) according to Claim 5 , with a step (270) of carrying out a transformation and / or filtering of the decrypted data (D) in order to anonymize the decrypted data (D) and / or to transform it into a format prescribed for the data (D). Method (235) according to one of the Claims 4 until 6th , wherein the step (250) of decrypting is carried out in a trustworthy environment (506) or the step (250) of decrypting and the step (240) of checking, the step of generating (260) and / or the step of performing ( 270) in a trusted environment (506). A method (280) for processing data, the method (280) comprising the steps of: - The steps (210, 220, 230) of the method (200) for managing data; and - the steps (240, 250, 260, 270) of the method (235) for evaluating data. Device (110) which is set up to carry out the steps of one of the methods (200, 235) according to one of the preceding claims in corresponding units (116, 118, 122, 124, 126, 132, 134, 136, 138) and / or to drive. Computer program which is set up to execute and / or control the steps of at least one of the methods (200, 235) according to one of the preceding claims. Machine-readable storage medium on which the computer program is based Claim 10 is stored.

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