The RINA verifiable credentials model

A verifiable credential is a digital document that holds information about somebody, such as a diploma, or about a company, such as a certificate, and can be verified by other individuals or systems. These documents are designed to be secure and can be safely shared online. 

This specification provides a standard way to express credentials on the Web in a way that is cryptographically secure, privacy respecting, and machine verifiable.

In a credentials verification system, there are three main roles:

• Holder: the entity who possesses and controls the "verifiable credential". For instance, if your organization obtains a digital certificate, the organization is the holder of that document. The holder can decide when and with whom to share its credential.
• Issuer: the entity or organization that issues the "verifiable credential" to the holder. It could be an employer, or an authority granting recognition such as a certification body. The issuer creates and assigns the credential to the holder.
• Verifier: The party that verifies the authenticity of the "verifiable credential". It might be an employer, an institution, a stakeholder, or a client requiring verification of the credential. The verifier examines the credential to ensure it is authentic and valid.

These three roles are essential in the process of managing and verifying digital credentials. The holder owns the credential, the issuer issues it, and the verifier checks it to confirm its authenticity.

In this context, RINA has the role of Issuer the verifiable credential, has the task of identifying the holder and making available the “Verifiable Data Registry” via Cloud platform.

The index:

• The format of RINA verifiable credentials
  • Basic structure
  • The “issuer” object
  • The “subjects” objects
  • The “proof” objects
• Data structure of the specific "subject"
  • Data structure of the “carbon_footprint”
  • Data structure of the “carbon_neutrality”
  • How to check the credential status

The format of RINA verifiable credentials

Basic structure

The credential has the following main information:

• “id”, represents the unique identifier of this credential
• the “issuer” object contains information on RINA Services SpA as issuer of the credential
• “issuance_date” and “expiration_date”, represent the date of first issue and expiration, if applicable, of this credential
• “subjects”, is an array of objects that constitute the subject of this credential
• “proof”, is an array of objects that contains the information necessary to verify the integrity and authenticity of this credential
• “schema”, contains the uri to credential validator in other words is a vocabulary that allows you to annotate and validate JSON credentials.

The “issuer” object

The information reported allows identification of the company name, VAT number, registered office and RINA website.

The “subjects” objects

This array contains object with the following structure:

The “subject_id” specify the target of this subject and the verification information, it is an enum field with the following options:

"subject_id"	Description
"carbon_footprint"	Carbon Footprint of product, service, process or organization
"carbon_neutrality"	Indicates that the carbon footprint occurring in the subject "carbon_footprint" has been offset. if this subject is present, the "carbon_footprint" one will also be present
"traceability"	Traceability of the production or service delivery phases
"recycled"	The amount of recycled used in product or in a process or from an organization
"product_origin"	The origin of material used in the product, process or by an organization
"product_origin"	The origin of material used in the product, process or by an organization
"energy_footprint"	Energy Footprint of product, service, process, or organization
"renewable_energy"	The amount of renewable energy used in product or in a process or from an organization

 

The fields "revision_number, "revision_date and "revision_reason" show information about the revision of this subject. The first version show a revision number equal to 0 and a revision reason equal to “First Issue”.

The "validity_status" field displays a uri that allows you to verify the validity of this specific object. 

The "subject_data" is an object composed of two objects:

• "product_data": in this object will be reported the main data used by the issuer to perform the verification activities
• "certificate_data": in this object will be reported the verification activity main outcomes such as, the references standards, the verification type, etc.

The "product_data" and "certificate_data" will show a specific object depending on the value of "subject_id". For further information see the paragraphs Subject types.

The “proof” objects

This array contains the same number of items of “subjects” array. Each item has the following structure:

The field "subject_id" it is the same described for the “subjects” objects. The "revision_number" identifies the revision of this proof and the field "created" identifies the data and time when this proof has been created. The "proof_purpose" specifies the purpose of this proof. The "proof_value" shows the cryptographic data for this proof and will be used to check authenticity and integrity.

Data structure of the specific "subject"

Data structure of the “carbon_footprint”

In case when the “subject_id” is equal to “carbon_footprint”, will be presented the following data structure:

"product_data"

This object has the following structure:

The "universal_id" shows the unique identifier of a product/service delivery or process for a producer.

The fields "sales_or_transportation_document_id" and "sales_or_transportation_document_date" show the identifier and date of a sales or transportation document for a manufacturer's product.
The “product_id” shows the product identifier within the sales or transport document.

The object “producer” shows the producer information with the following structure:

The information reported allows identification of the producer in terms of company name, VAT number, address, the identifier that RINA has been assigned to shipment site, the shipment site name, country and city.

The object “recipient” shows the information related to the product recipient with the following structure:

The information reported allows identification of the recipient in terms of company name, address, and email.

The "quantity" and "measurement_unit" fields report the information regarding the product quantity.

The object "product_info" shows additional information about the product not used by the issuer to perform the verification activity.

"certificate_data"

The object has the following structure:

The "certification_subject_type" field reports the type of declaration issued by the issuer with respect to the reference standards shows in the "standard_references" field.

The "web_page_uri" shows the URI of the web page that graphically represents this credential to be readable by interested parties.

The fields "carbon_footprint" and "carbon_emission" shows the amount of CO2e respectively for unitary product quantity and for the specific product quantity.

Data structure of the “carbon_neutrality”

When this structure is reported the subject of “carbon_footprint” is also present.

"product_data"

The "universal_id" shows the unique identifier of a product/service delivery or process for a producer. The “product_id” shows the product identifier within the sales or transport document.

"certificate_data"

The "certification_subject_type" field reports the type of declaration issued by the issuer with respect to the reference standards shows in the "standard_references" field.

The "web_page_uri" shows the URI of the web page that graphically represents this credential to be readable by interested parties. 

The “carbon_credit_projects_used” is an array of object with the following fields: 

• “id”: it is a RINA identifier linked to carbon credit offsetting
• “name”, “serial_number”, “country”, “standard”, “issuer”, “emission_data”, are information about the carbon credit project
• "amount_used", "measurement_unit” are information about the use of the credit to offsetting the CO2e verified in the subject “carbon_footprint”.

How to check the credential status

The uri in the "validity_status" field in the subject object show the validity of a subject of a credential, when call it return the following structure: