## Union of http://smart.who.int/trust/CodeSystem/KeyUsage-DEV and http://smart.who.int/trust/CodeSystem/KeyUsage-DEV

This is the CodeSystem that contains all the codes in WHO GDHCN Key Usage CodeSystem - DEV (http://smart.who.int/trust/CodeSystem/KeyUsage-DEV) and WHO GDHCN Key Usage CodeSystem - DEV (http://smart.who.int/trust/CodeSystem/KeyUsage-DEV). E.g. what you have to deal with if you get resources containing codes in either of them

### CodeSystem

Generated Narrative: CodeSystem 284bdbc3-b353-4e88-9a10-a1a41e3576bd-17

This code system `http://hl7.org/fhir/comparison/CodeSystem/284bdbc3-b353-4e88-9a10-a1a41e3576bd-17` defines codes, but no codes are represented here

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