The Macao SAR Government has officially joined the Public Key Directory (PKD) of the International Civil Aviation Organization (ICAO) since 28 September 2010, becoming the 19th participant in the name of “Macao, China”. This participation not only helps the promotion of Macao SAR electronic travel documents to other countries, but also enhances the international recognition of Macao SAR electronic travel documents.

Public Key Infrastructure is a significant component of electronic travel documents. It creates an electronic signature (which is created by computing the information mathematically, and acts as if a hand-written signature on an electronic document) for the information stored in the chip embedded in the electronic travel document with an electronic certificate (a digital document for authenticating the identity of the issuing authority.), ensuring that the chip information of the travel document has not been altered. The “Country Signing Certificate Authority Certificate”, the “Document Signer Certificate” and the “Certificate Revocation List” have to be used in the process.

The Public Key Directory is a platform where the abovementioned “Document Signer Certificate” and “Certificate Revocation List” are stored. It provides a reliable, secure and efficient method for each member country and region to exchange the abovementioned certificates, facilitating the authentication of the chip information of travel documents for the immigration control department of every country and region.