ICAO is acting as a Certification Authority (CA) for the purposes of signing the ICAO Health Master List.
The root certificate (CA certificate) is used to digitally sign the Master List signer certificate that itself signs the Master List, in accordance with ICAO Doc9303. The Master List Signer certificate is stored in the Master List itself, while the CA public key certificate is made available here.
This root certificate allows the user to confirm that the Master List is issued by ICAO and that the data has not been altered since issuance.
The root certificate is made available along with a Certificate Revocation List (CRL) which includes any certificates under this CA that have been revoked.
The CA certificate is associated with the 3-letter code IAO and the 2-letter code IA.
The CA certificate is available
here.
The CRL is available
here.
