DE102020210810A1 - Method and device for mutually evaluating service providers and service recipients using a decentralized transaction database - Google Patents

Abstract

Method (10) for evaluating a provider (20) of a service (21) using a decentralized transaction database, characterized by the following features:
- the provider (20) is subjected to an evaluation by a recipient (22) of the service (21) (11) or vice versa,
- a data record (23) last added to the transaction database is mapped to a first spread value (12) using a spread value function,
- the evaluation and the first scatter value are summarized (13) in a new data set (23),
- the new record (23) is added to the transaction database and mapped under the hash function to a second hash (14) and
- the new data set (23) or the second scatter value are managed by a selected (28) third party (24) who is not acting in the interest of the evaluated party and is made available to interested parties (25) in the service (21) on request (27). (15).

Description

The present invention relates to a method for evaluating a service provider using a decentralized transaction database. The present invention also relates to a corresponding device, a corresponding computer program and a corresponding storage medium.

State of the art

Any protocol in computer networks that brings about an agreement (consensus) with regard to the sequence of certain transactions is referred to as a decentralized transaction system, transaction database or distributed ledger. A common form of such a system is based on a block chain (blockchain) and forms the basis of numerous so-called cryptocurrencies.

U.S. 2019/0325432 A1 discloses a blockchain-based reputation system.

Blockchains are also used, for example, in the context of so-called decentralized identity (DID) and in particular self-sovereign identity (SSI), by means of which individual identity holders manage an identity and the use of their personal data without the involvement of an intermediary or controlled by a central authority. Specifically, the DID can serve, for example, as verifiable proof (verifiable credential) of claimed properties, which in turn can be provided by a verifiable presentation (verifiable presentation).

DE212019000019U1 discloses a system that authorizes the bearer of an identity document, comprising: an identity provider for providing a decentralized identity to the bearer; means for providing the bearer with digitally signed biometrics related to the identity document, the biometrics being signed by a trust anchor and validated as issued to the decentralized identity, the biometrics including an image of the bearer; a means of providing the wearer's decentralized identity and biometric data, including the image, to an authority for verification prior to the wearer's trip, which is responsible for the wearer's entry permit, whereby after the verification the wearer obtains an authorization from the authority receives; an image capture system for capturing an image of the wearer upon arrival of the wearer; an image matching system for matching the image of the carrier with images of a plurality of carriers authorized by the agency; and a control gate for granting an entry permit for the carrier after successful matching.

Disclosure of Invention

The invention provides a method for evaluating a service provider and the service recipient using a decentralized transaction database, a corresponding device, a corresponding computer program and a corresponding storage medium according to the independent claims.

The approach according to the invention is based on the knowledge that in known reputation systems there is usually a central provider which on the one hand offers the possibility of evaluating another party, but on the other hand is ultimately the owner of the reputation data provided. On the one hand, this results in a dependency of the various parties who want to mutually evaluate their interactions, and on the other hand, an information asymmetry in favor of the operator. In addition, these systems are vulnerable, since the rating function can easily be misused, especially since it often does not require proof of an interaction to create a rating, but only an account on the respective rating platform.

In conventional reputation systems, both an improvement in the self-presentation and a deterioration in the representation of a competitor are possible with little effort for the reasons mentioned. In addition, the evaluations are usually subject to enormous arbitrariness and subjectivity, so that in many cases they are unjustified and difficult to understand.

The proposed solution is also based on the insight that a reputation system for the autonomous interaction of Internet-enabled devices (machine-to-machine, M2M) in decentralized systems is of great importance, since there is no intermediary who ensures compliant behavior and who takes responsibility in case of doubt . A reputation system that dispenses with an intermediary therefore serves to build trust between mutually unknown parties.

Against this background, an advantage of the method according to the invention lies in its suitability for ensuring both the data sovereignty of the evaluated parties and the correctness of the evaluations.

The measures listed in the dependent claims are advantageous developments and improvements in the independent Claim specified basic idea possible. Evidence of the authorization to evaluate the respective service provider can be provided. In this way, the arbitrary issuing of ratings by actors who have never interacted with the rated party can be prevented.

character list

• 1 das Flussdiagramm eines Verfahrens zum Bewerten eines Leistungserbringers gemäß einer ersten Ausführungsform.
• 2 die Sicherstellung der Integrität der Bewertungen.
• 3 die Überprüfung der Korrektheit der Bewertungen.
• 4 die Rollenverteilung zwischen den Akteuren des Verfahrens.
• 5 schematisch ein Steuergerät gemäß einer zweiten Ausführungsform.

Embodiments of the invention are shown in the drawings and explained in more detail in the following description. It shows:

• 1 the flow chart of a method for evaluating a service provider according to a first embodiment.
• 2 ensuring the integrity of reviews.
• 3 checking the correctness of the ratings.
• 4 the distribution of roles between the actors in the process.
• 5 schematically a control unit according to a second embodiment.

Embodiments of the invention

1 illustrates the basic steps of a method (10) according to the invention, the sequence of which will now be explained with reference to the following figures. After a successfully completed interaction, which involves the exchange of money, goods or services between two parties, they can send each other an evaluation (process 11). Ratings are generated as single atomic records and can be issued in the form of Verifiable Reputation Credentials (VRC), similar to a certificate. The data records can also correspond to another form. The rating is only transmitted to the rated party, which means that this party is also the sole owner of this rating data.

These VRCs are collected by the addressee of the assessment and can be made available to a potential next interaction partner in the form of a representation whose correctness can be checked by the new interaction partner.

In order to make this possible, a hash value of the last VRC is generated (process 12) by the service recipient to be evaluated (hereinafter referred to as “receiver”) when an evaluation is issued. Provider") was transmitted as part of the presentation. This spread value becomes, like 2 illustrated, now entered by the recipient (22) in his newly created assessment data record (VRC) (23) (process 13 - 1 ) and signed with its DID. Thus, after the record (23) has been added to a transaction database, the provider (20) is not able to remove any previous negative assessment from this database, since each record (23) is cryptographically linked to its predecessor.

However, without further measures, the provider (20) could discard the data record (23) before it is added to the transaction database if the evaluation contained does not appeal to him and he does not wish to present it. In order to prevent this, a trustworthy third party (24) is provided, which is used to store the scatter value of the most recent data set (23), to make it available to the potential new interaction partner and thus to ensure that the data set (23) can be verified. Alternatively, the data set (23) itself can be managed by the third party (24); However, the disclosure of only the scatter value guarantees better data protection (privacy), since the third party (24) does not gain knowledge of the evaluation contained in the data record (23) in this way.

In detail, the procedure is running (10 - 1 ) as follows: The receiver (22) maps the VRC last added in the presentation/collection of evaluation data sets (verifiable presentation) of the service provider to a scatter value (process 12 - 1 ) and combines this with its evaluation into a new data set (23) (process 13 - 1 ). It then forms the scatter value of this data set (process 14 - 1 ) and transmits the latter in the form of a signed message to the third party (24).

If now, as in 3 shown, a new prospect (25) in the service offered (21) would like to see the ratings of the provider (20), he can check the correctness and completeness of the ratings with the help of the third party (24) by using the scatter value of the latest data set (23 ) compared with that kept by the third party (24) (process 15 - 1 ). If there is a match, the ratings are correct and the prospect (25) knows that he can trust the provider (20).

The connections as well as the roles of this evaluation scenario are explained in 4 illustrated. In the present embodiment, the third party (24) selected by the provider (20) not only serves the recipient (22) by certifying (30) the integrity of the assessment contained in the new data record (23), but also administers it proof (26) provided by the recipient (22) that he has used the service (21) of the provider (20) at all and is therefore entitled to evaluate it. The provider (20) can have this authorization confirmed by the third party (24) before adding the new data record (23). The relevant evidence (26) may have been made available to the recipient (22) by the provider (20) of the service (21) or the use of the service (21) by the recipient (22) may otherwise prove. Thus, if one of the parties (20, 22) wishes to prevent the evaluation, it is ensured that the other party can provide the proof (26) instead.

Another aspect of the procedure (10) is to enable autonomous and objective assessments, since in the context of the Internet of Things (loT) products and services can be assessed in a largely standardized and neutral manner. A preferred embodiment therefore provides measurable properties for evaluating a product or service. This ensures that there is no arbitrariness in the assessment.

To illustrate this, the autonomous assessment of a digital service, such as the provision of a database, should be considered. Criteria such as availability, processing time, consistency and failure tolerance (partition tolerance) could play a role here. All of these are measurable criteria that allow for an objective assessment. The same applies to most use cases of the loT, in which machines act autonomously and complete transactions independently. An optional further security measure is that the evaluations are not subject to a uniform calculation method, but are interpreted by each market participant in their own way. It is therefore not effective to attack or manipulate the calculation process.

This method (10) can be implemented, for example, in software or hardware or in a mixed form of software and hardware, for example in a control unit (50), such as the schematic representation of FIG 5 clarified.

QUOTES INCLUDED IN DESCRIPTION

This list of the documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• US 2019/0325432 A1 [0003]
• DE 212019000019 U1 [0005]

Claims (10)

Method (10) for evaluating a provider (20) of a service (21) using a decentralized transaction database, characterized by the following features: - the provider (20) is subjected to an evaluation by a recipient (22) of the service (21) (11) , - a data record (23) last added to the transaction database in the presentation/collection of evaluation data records is mapped under a scatter value function to a first scatter value (12), - the evaluation and the first scatter value are combined (13) in a new data record (23) , - the new record (23) is added to the transaction database and mapped to a second spread (14) under the hash function, and - the new record (23) or second hash is managed by a selected (28) third party (24) and interested party (25) Provided (15) at performance (21) on request (27). Method (10) according to claim 1 , characterized by the following features: - the third party (24) also manages a proof (26) of the recipient (22) about an authorization to evaluate the provider (20) and - before adding the new data record (23), the provider ( 20) the authorization confirmed (29) by the third party (24). Method (10) according to claim 2 , characterized by at least one of the following features: - the proof (26) is provided to the recipient (22) by the provider (20) of the service (21) or - the proof (26) proves that the service (21) has been used by the receiver (22). Method (10) according to claim 2 or 3 , characterized by at least one of the following features: - the new data record (23) is signed by the recipient (22) of the service (21), - the second scatter value is signed by the recipient (22) of the service (21) or - the proof ( 26) about the authorization is signed by the recipient (22) of the service (21). Method (10) according to any one of Claims 1 until 4 , characterized by the following features: - the ratings define a decentralized identity of the provider (20) in the transaction database and - the interested parties (25) request, with reference to the identity, if necessary, a representation (28) of the ratings that can be checked using the transaction database. Method (10) according to claim 5 , characterized by the following features: - the decentralized identity is a self-sovereign identity of the provider (20) and - the representation (28) is carried out by the provider (20). Method (10) according to any one of Claims 1 until 6 , characterized by the following features: - the transaction database comprises a block chain and - the addition of the data records comprises a linking of corresponding data blocks to the block chain. Computer program which is set up, the method (10) according to one of Claims 1 until 7 to execute. Machine-readable storage medium on which the computer program claim 8 is saved. Device (50) which is set up, the method (10) according to one of Claims 1 until 7 to execute.

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