WHO SMART Trust
1.1.6 - CI Build

WHO SMART Trust, published by WHO. This guide is not an authorized publication; it is the continuous build for version 1.1.6 built by the FHIR (HL7® FHIR® Standard) CI Build. This version is based on the current content of https://github.com/WorldHealthOrganization/smart-trust/tree/gherkintests and changes regularly. See the Directory of published versions

## CodeSystem: WHO GDHCN Key Usage CodeSystem (Experimental)

Official URL: http://smart.who.int/trust/CodeSystem/KeyUsage | Version: 1.1.6
Active as of 2025-09-10 | Computable Name: KeyUsage

CodeSystem for GDHCN Key Usage that has usage codes for verification keys published to the Trust Network as defined by the certificate governance

This Code system is referenced in the content logical definition of the following value sets:

- KeyUsage

This case-insensitive code system `http://smart.who.int/trust/CodeSystem/KeyUsage` defines the following codes:

Code | Display | Definition
SCA | Signer Certificate Authority (SCA) | A certificate which acts a trust anchor in the verification of the certificate chain for the DSCs issued by a Trust Network participant
DSC | Document Signing Certificate (DSC) | A certificate which may be used to verify a digital signature within a Verfifiable Digital Health Certificate
DECA | Data Exchange Certificate Authority (DECA) | A certificate which acts a trust anchor in the verification of the certificate chain for the DESCs issued by a Trust Network Participant
DESC | Data Exchange Signing Certificate (DESC) | A certificate which may be used to initiate a secure data exchange connection (e.g. mTLS) between Trust Network Participants
TLS | Transport Layer Security (TLS) | Used for establishing (m)TLS connections with systems, in particular between the Trust Network Gateway and backend systems of a Trust Network Participant
UP | Upload (UP) | Used to verify digital signature of cryptographically signed content uploaded to services within the Global Digital Health Certification Network, in particular the Trust Network Gateway