A computer-implemented method includes: verifying, by a trusted server, an identity of a first terminal; determining that the verification is a success; based on determining that the verification is a success, determining, using a remote attestation protocol, that the first terminal is in a trusted state; and based on determining that the first terminal is in the trusted state, issuing a digital certificate including a trusted identifier to the first terminal, in which the digital certificate is usable by a second terminal to verify the identity of the first terminal.