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Version: 24.05

Policies in Catena-X

Data Sovereignty in Catena-X​

This page extends on the previous section's fundamentals and introduces conventions specific to the Catena-X Dataspace. It assumes basic knowledge on Policies and their processing. Please go back to the fundamentals if that's unfamiliar.

Catena-X recommends to focus on permission property to further specify the contracts' details. In general, every data provider can decide on his or her own under which conditions their data datasets (assets) are shared in the network. In practice, this works as long as both parties, Provider and Consumer, have the same understanding of its legal meaning. Therefore, standardized such Constraints with their leftOperands and rightOperands are key for automation. Still, individual freedom of contract is a very high good and is still possible.

This guidance is however also relevant for Enablement Service Providers building components enabling connectivity to the Dataspace (as specified in CX-0018). The authoritative resource for schemas is the Catena-X ODRL Profile. It is also available via the Policy Hub that is operated centrally. The API is documented in this Repository and can be accessed with an access token to the Portal. It's a convenience feature for the negotiating parties to check if a given offer matches the policy constraints agreed by the Catena-X association - for instance by keeping a definite list of valid rightOperands to a particular leftOperand in a Constraint.

As mentioned in the primer on policies, Providers and Consumers must have a common understanding of the meaning and consequences of odrl:Offers and, on a more granular level, their odrl:Constraints. That's why there is a set of predefined odrl:Constraints - all of which have to be accepted explicitly and some checked against a Consumer's VP additionally. They are formalized in the Catena-X ODRL profile which extends the regular ODRL vocabulary. Since usage or contract policies are highly dependent on the use case, they are described by them in their associated KITs and only general elements are explained in the following.

Here's a non-normative overview of these extensions:

Use Case Framework Constraints​

Use Case Framework Constraints are references to legally binding documents set up by the Catena-X association. They govern the "who, with whom, what, where from and where to, why, how, and when" of Data Sharing in Catena-X Use-Cases (Source). Use Case Frameworks are roughly structured along the lines of business scenarios under which a set of business partners want to exchange data.

Each Participant commits to a set of Use Case Frameworks during Onboarding. They are granted a set of VCs as proof of that commitment. Consequently, Use Case Framework Constraints belong to the kind of odrl:Constraints that have to be checked against a VP. The complete set is listed in the most current version of standard CX-0050 Framework Credential. Use Case Frameworks are referred to in a machine-readable way in a Provider's Offers. When a Consumer starts the negotiation for said offer, not only will the Policy in the ContractRequestMessage be checked but also his Credentials. Here's an example of an odrl:Constraint referencing a Use Case Framework and invoking the VC-check:

{
  "@context": {
    "odrl": "http://www.w3.org/ns/odrl/2/"
  },
  "odrl:leftOperand": "https://w3id.org/catenax/policy/FrameworkAgreement",
  "odrl:operator": {
    "@id": "odrl:eq"
  },
  "odrl:rightOperand": "traceability:1.0"
}

Usage Purposes​

Purposes are usually part of a Use Case Framework and restrict the purpose the Consumer is privileged to use the obtained data for. Unlike a Use Case Framework Constraint, the purposes are NOT checked against VCs, thus necessary for a successful negotiation mechanism is only the Consumer's consent to the Offer. Versions for UsagePurpose rightOperands are typically 1-digit. The complete list of usage purposes in Catena-X is publicly available in the CX ODRL Profile. The corresponding documents are linked on the Catena-X e.V. homepage. Here's an example from the Use Case Framework Traceability:

Predefined PolicyTypically used where?Predefined Purpose
cx.core.qualityNotifications:1Notification APIThe data can be used for quality analysis to identify and select affected components and to send quality notifications to affected customers or suppliers

A odrl:Constraint referencing this purpose looks like this:

{
  "@context": {
    "odrl": "http://www.w3.org/ns/odrl/2/"
  },
  "odrl:leftOperand": "https://w3id.org/catenax/policy/UsagePurpose",
  "odrl:operator": {
    "@id": "odrl:eq"
  },
  "odrl:rightOperand": "cx.core.qualityNotifications:1"
}

Contract References​

Contract References by default aren't checked against credentials either. They are a vehicle to refer to contracts that are not governed by the Catena-X association - for instance bilaterally. Referencing such a contract's identifier can be achieved via an odrl:Constraint like this:

{
  "@context": {
    "odrl": "http://www.w3.org/ns/odrl/2/"
  },
  "odrl:leftOperand": "https://w3id.org/catenax/policy/ContractReference",
  "odrl:operator": {
    "@id": "odrl:eq"
  },
  "odrl:rightOperand": "contract-123456789"
}

Chaining Constraints​

If a Policy is supposed to hold multiple constraints, Data Providers may chain them via a logical AND. This can be achieved via an odrl:and object encapsulating multiple other odrl:Constraints or entering a list of them into the odrl:constraint property. The example below contains both versions.

Constraints that are supposed to be checked with a logical OR should be published as separate Data Offers.

Example​

This specific Catalog contains one single dcat:Dataset, called "json-1-paper". It is the only entry in the top-level dcat:dataset property. To access this Dataset, the Consumer can choose between two Offers (see the odrl:hasPolicy property):

  • "Y29udHJhY3QtYmlsYXRlcmFsLXBhcGVyLWV4YW1wbGUtMg==:anNvbi0xLXBhcGVy:ZDA4ZDM5OTgtOGY5ZS00MzBmLThjZDEtZmYwOWQxMmQxYzk5"
  • "Y29udHJhY3QtYmlsYXRlcmFsLXBhcGVyLWV4YW1wbGUtMQ==:anNvbi0xLXBhcGVy:ODFkMDI2MWYtNDNlNi00ZTIxLWJkMWYtZmFmZTI3MWQwYzhj"
{
  "@context": {
    "@vocab": "https://w3id.org/edc/v0.0.1/ns/",
    "edc": "https://w3id.org/edc/v0.0.1/ns/",
    "tx": "https://w3id.org/tractusx/v0.0.1/ns/",
    "dcat": "http://www.w3.org/ns/dcat#",
    "dct": "https://purl.org/dc/terms/",
    "odrl": "http://www.w3.org/ns/odrl/2/",
    "dspace": "https://w3id.org/dspace/v0.8/"
  },
  "@id": "693e9b66-04f2-4bfb-b3cd-daf5857b47c9",
  "@type": "dcat:Catalog",
  "dcat:dataset": [
    {
      "@id": "json-1-paper",
      "@type": "dcat:Dataset",
      "odrl:hasPolicy": [
        {
          "@id": "Y29udHJhY3QtYmlsYXRlcmFsLXBhcGVyLWV4YW1wbGUtMg==:anNvbi0xLXBhcGVy:ZDA4ZDM5OTgtOGY5ZS00MzBmLThjZDEtZmYwOWQxMmQxYzk5",
          "@type": "odrl:Set",
          "odrl:permission": {
            "odrl:action": {
              "@id": "http://www.w3.org/ns/odrl/2/use"
            },
            "odrl:constraint": {
              "odrl:and": [
                {
                  "odrl:leftOperand": "https://w3id.org/catenax/policy/FrameworkAgreement",
                  "odrl:operator": {
                    "@id": "odrl:eq"
                  },
                  "odrl:rightOperand": "traceability:1.0"
                },
                {
                  "odrl:leftOperand": "https://w3id.org/catenax/policy/UsagePurpose",
                  "odrl:operator": {
                    "@id": "odrl:eq"
                  },
                  "odrl:rightOperand": "cx.core.industrycore:1"
                }
              ]
            }
          },
          "odrl:prohibition": [],
          "odrl:obligation": []
        },
        {
          "@id": "Y29udHJhY3QtYmlsYXRlcmFsLXBhcGVyLWV4YW1wbGUtMQ==:anNvbi0xLXBhcGVy:ODFkMDI2MWYtNDNlNi00ZTIxLWJkMWYtZmFmZTI3MWQwYzhj",
          "@type": "odrl:Set",
          "odrl:permission": {
            "odrl:action": {
              "@id": "http://www.w3.org/ns/odrl/2/use"
            },
            "odrl:constraint": [
              {
                "odrl:leftOperand": "https://w3id.org/catenax/policy/FrameworkAgreement",
                "odrl:operator": {
                  "@id": "odrl:eq"
                },
                "odrl:rightOperand": "traceability:1.0"
              },
              {
                "odrl:leftOperand": "https://w3id.org/catenax/policy/ContractReference",
                "odrl:operator": {
                  "@id": "odrl:eq"
                },
                "odrl:rightOperand": "contract-123456789"
              },
              {
                "odrl:leftOperand": "https://w3id.org/catenax/policy/UsagePurpose",
                "odrl:operator": {
                  "@id": "odrl:eq"
                },
                "odrl:rightOperand": "cx.core.industrycore:1"
              }
            ]
          },
          "odrl:prohibition": [],
          "odrl:obligation": []
        }
      ],
      "dcat:distribution": [
        {
          "@type": "dcat:Distribution",
          "dct:format": {
            "@id": "HttpData-PULL"
          },
          "dcat:accessService": "911f5da0-c9ee-4259-9a95-39428d08f777"
        }
      ],
      "version": 1.0,
      "content-type": "application/json",
      "name": "json-1-paper",
      "description": "Asset json-1-paper for test purposes",
      "id": "json-1-paper"
    }
  ],
  "dcat:service": {
    "@id": "911f5da0-c9ee-4259-9a95-39428d08f777",
    "@type": "dcat:DataService",
    "dct:terms": "connector",
    "dct:endpointUrl": "https://provider-dsp-end.point/api/v1/dsp"
  },
  "participantId": "PROVIDER-BPNL"
}

Notice​

This work is licensed under the CC-BY-4.0.