{
  "resourceType" : "CodeSystem",
  "id" : "KeyUsage",
  "text" : {
    "status" : "generated",
    "div" : "<div xmlns=\"http://www.w3.org/1999/xhtml\"><p class=\"res-header-id\"><b>Generated Narrative: CodeSystem KeyUsage</b></p><a name=\"KeyUsage\"> </a><a name=\"hcKeyUsage\"> </a><p>This case-insensitive code system <code>http://smart.who.int/trust/CodeSystem/KeyUsage</code> defines the following codes:</p><table class=\"codes\"><tr><td style=\"white-space:nowrap\"><b>Code</b></td><td><b>Display</b></td><td><b>Definition</b></td></tr><tr><td style=\"white-space:nowrap\">SCA<a name=\"KeyUsage-SCA\"> </a></td><td>Signer Certificate Authority (SCA)</td><td>A certificate which acts a trust anchor in the verification of the certificate chain for the DSCs issued by a Trust Network participant</td></tr><tr><td style=\"white-space:nowrap\">DSC<a name=\"KeyUsage-DSC\"> </a></td><td>Document Signing Certificate (DSC)</td><td>A certificate which may be used to verify a digital signature within a Verfifiable Digital Health Certificate</td></tr><tr><td style=\"white-space:nowrap\">DECA<a name=\"KeyUsage-DECA\"> </a></td><td>Data Exchange Certificate Authority (DECA)</td><td>A certificate which acts a trust anchor in the verification of the certificate chain for the DESCs issued by a Trust Network Participant</td></tr><tr><td style=\"white-space:nowrap\">DESC<a name=\"KeyUsage-DESC\"> </a></td><td>Data Exchange Signing Certificate (DESC)</td><td>A certificate which may be used to initiate a secure data exchange connection (e.g. mTLS) between Trust Network Participants</td></tr><tr><td style=\"white-space:nowrap\">TLS<a name=\"KeyUsage-TLS\"> </a></td><td>Transport Layer Security (TLS)</td><td>Used for establishing (m)TLS connections with systems, in particular between the Trust Network Gateway and backend systems of a Trust Network Participant</td></tr><tr><td style=\"white-space:nowrap\">UP<a name=\"KeyUsage-UP\"> </a></td><td>Upload (UP)</td><td>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</td></tr></table></div>"
  },
  "url" : "http://smart.who.int/trust/CodeSystem/KeyUsage",
  "version" : "1.1.6",
  "name" : "KeyUsage",
  "title" : "WHO GDHCN Key Usage CodeSystem",
  "status" : "active",
  "experimental" : true,
  "date" : "2026-02-24T09:54:30+00:00",
  "publisher" : "WHO",
  "contact" : [{
    "name" : "WHO",
    "telecom" : [{
      "system" : "url",
      "value" : "http://who.int"
    }]
  }],
  "description" : "CodeSystem for GDHCN Key Usage that has usage codes for verification keys published to the Trust Network as defined by the [certificate governance](concepts_certificate_governance.html) for Production environment",
  "jurisdiction" : [{
    "coding" : [{
      "system" : "http://unstats.un.org/unsd/methods/m49/m49.htm",
      "code" : "001"
    }]
  }],
  "caseSensitive" : false,
  "content" : "complete",
  "count" : 6,
  "concept" : [{
    "code" : "SCA",
    "display" : "Signer Certificate Authority (SCA)",
    "definition" : "A certificate which acts a trust anchor in the verification of the certificate chain for the DSCs issued by a Trust Network participant"
  },
  {
    "code" : "DSC",
    "display" : "Document Signing Certificate (DSC)",
    "definition" : "A certificate which may be used to verify a digital signature within a Verfifiable Digital Health Certificate"
  },
  {
    "code" : "DECA",
    "display" : "Data Exchange Certificate Authority (DECA)",
    "definition" : "A certificate which acts a trust anchor in the verification of the certificate chain for the DESCs issued by a Trust Network Participant"
  },
  {
    "code" : "DESC",
    "display" : "Data Exchange Signing Certificate (DESC)",
    "definition" : "A certificate which may be used to initiate a secure data exchange connection (e.g. mTLS) between Trust Network Participants"
  },
  {
    "code" : "TLS",
    "display" : "Transport Layer Security (TLS)",
    "definition" : "Used for establishing (m)TLS connections with systems, in particular between the Trust Network Gateway and backend systems of a Trust Network Participant"
  },
  {
    "code" : "UP",
    "display" : "Upload (UP)",
    "definition" : "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"
  }]
}