Expert ID card and its photocopy, and application form for expert digital certificate. A CA certificate is an electronic certificate issued by a CA, also known as a digital certificate. A certificate mainly includes the identity information of the certificate owner, the signature of the CA organization, the public key and the private key. Yantai needs an expert ID card and a copy to apply for a ca digital certificate, and an application form for an expert digital certificate. Yantai, a prefecture-level city under the jurisdiction of Shandong Province, is one of the central cities of Shandong Peninsula, an important port city around Bohai Sea and a national historical and cultural city.