# Transactions - WHO SMART Trust v1.4.0

* [**Table of Contents**](toc.md)
* [**Data Models and Exchange**](data_exchange.md)
* **Transactions**

## Transactions

### Publish Keys

#### Trigger Events

The Trust Network Participant, or one of its authorized Issuers, generates a new public-private key pair for use for document signing.

#### Message Semantics

See the [EU DCC Open API](openapi/index.md#/GDHCN/postTrustedCertificate) documentation. The key usage is DSC for Document Signing Certificate

#### Expected Actions

The Trust Anchor will validate the submitted key material and distribute it to other Trust Network Participants

### Mirror Local PKD

#### Trigger Events

#### Message Semantics

#### Expected Actions

Steps include:

* Local PKD onboarding (one-time). Onboarding may include evaluating Local PKD format, providing the Federated PKD access, and signing of business agreements.
* Local PKD public keys are mirrored (periodic)
* Mirrored public keys are merged into a master list (periodic)
* Master list is digitally signed for distribution

Local PKDs participating in the Federated PKD are expected to:

* Have an existing public key infrastructure used for issuing trusted health documents (e.g. COVID credentials)
* Have permissions/policies in place that allow sharing the public keys
* Can share public keys in one of the following formats: 
* X.509
* JSON Web Keys (JWK)
* [Decentralized Identifiers](https://www.w3.org/TR/did-1.0/) (DID) according to the [GDHCN specification](concepts_did_gdhcn.md) specification.
 

Federated PKDs are expected to:

* Have a means for retrieving local public key directories / nodes members represented in the aggregation services
* Have permissions/policies in place that allow sharing the public keys from trust node members
* Have an existing public key infrastructure used for signing list of keys my node members
* Can share list of public keys in the following format: 
* [Decentralized Identifiers](https://www.w3.org/TR/did-1.0/) (DID) according to the [GDHCN specification](concepts_did_gdhcn.md) specification.
 

### Sign Health Certificate (HCERT) Claim

#### Trigger Events

The claim payload of a [HCERT](hcert_spec.md) has been generated and is ready to be signed by an Issuer acting on behalf of a Trust Network Participant.

#### Message Semantics

The output should be a valid signed [HCERT](hcert_spec.md)

#### Expected Actions

<h4 id="put_keys_api} Publish Verification Keys - API

#### Trigger Events

A Trust Network Partcipiant publish keys to the Trust Network Gateway for use by Verification Applications. Keys may be coded for a variety of uses including following the [certificate governance](concepts_certificate_governance.md) according to their [**$usage**](ValueSet-KeyUsage.md) and trust [**$domain**](ValueSet-Domains.md)

#### Message Semantics

See [Swagger API](openapi/index.md)

#### Expected Actions

### Retrieve Verification Keys - DID

#### Trigger Events

#### Message Semantics

Keys should be retrieved using the [GDHCN DID](concepts_did_gdhcn.md) specification.

#### Expected Actions

Once a Verification Application has onboarded to the Trust Network it may retrieve verification keys. The retrieved list of verificaiton keys may be used for the following busines processes:

* Onboarding a Federated PKD by retrieving the signing key used to sign the master list (one-time).
* Retrieving the master list from the Federated PKD and verifying the signature (periodic).
* Deserializing a Verifiable QR code (e.g. vaccine credential 2D bar-code) to determine the key id.
* Retrieving the public key associated with the key id from the master list, or using a cached key.
* Verifying 
* the cryptographic signature within the 2D barcode.
* the authority of the issuer to issue this type of certificate with this key.
* the expiration date of the keys.
* the expiration date from the certificate.
* the certificate is not part of revocation lists available.
* the issuing key is still present on a trust list by the issuing authority (not revoked).
* the issuing key is still present on the trust list of the verification authority.
* the name/identity on the certificate matches an ID document.
* the business rules of the verification jurisdiction pass for the certificate.
 

### Retreive Verification Keys - API

#### Trigger Events

#### Message Semantics

See [Swagger API](openapi/index.md)

#### Expected Actions

Once a Verification Application has onboarded to the Trust Network it may retrieve verification keys. The retrieved list of verificaiton keys may be used for the following busines processes:

* Onboarding a Federated PKD by retrieving the signing key used to sign the master list (one-time).
* Retrieving the master list from the Federated PKD and verifying the signature (periodic).
* Deserializing a Verifiable QR code (e.g. vaccine credential 2D bar-code) to determine the key id.
* Retrieving the public key associated with the key id from the master list, or using a cached key.
* Verifying 
* the cryptographic signature within the 2D barcode.
* the authority of the issuer to issue this type of certificate with this key.
* the expiration date of the keys.
* the expiration date from the certificate.
* the certificate is not part of revocation lists available.
* the issuing key is still present on a trust list by the issuing authority (not revoked).
* the issuing key is still present on the trust list of the verification authority.
* the name/identity on the certificate matches an ID document.
* the business rules of the verification jurisdiction pass for the certificate.
 

Keys should be retrieved using the [GDHCN DID](concepts_did_gdhcn.md) specification.

### Request Business Rule Updates - API

#### Trigger Events

#### Message Semantics

See [Swagger API](openapi/index.md)

#### Expected Actions

### Request Business Rule Updates - API

#### Trigger Events

#### Message Semantics

Shall act as a Business Rules Library:

* Expresses health policies (e.g. “Needs full course of vaccine”) as executable business rule using the Clinical Quality Language (CQL) as a FHIR Library Resource
* Publishes business rules as FHIR Library resources with a trust health service

Optionally:

* Provide digital signagure of business rule as FHIR Provenance resource
* Provides public key to PKD

#### Expected Actions

### Execute Business

#### Trigger Events

#### Message Semantics

#### Expected Actions

Verification App:

* Pre-Condition: Perform Federated Verification workflow on one ore more QR-code
* Identify one (or more) business rule(s) to be exectued according to use case

Optionally:

* Retrieves business rule signing public key from PKD (either Local PKD or via Aggregating/ Federated PKD)
* Verifies authenticity of business rule
* Map QR-code content into requiste FHIR resources using FHIR Structure Maps
* Execute CQL businns rule on FHIR resource content

### Request Value Sets - API

#### Trigger Events

#### Message Semantics

See [Swagger API](openapi/index.md)

#### Expected Actions

### Request Value Sets - FHIR

#### Trigger Events

#### Message Semantics

See [IHE Sharing Value Sets and Concept Maps](https://profiles.ihe.net/ITI/SVCM/) for transactions against a Terminology Service.

#### Expected Actions

### Execute Business

#### Trigger Events

#### Message Semantics

#### Expected Actions

