Abstract: The present invention relates to a cyber security authentication method. The method includes the following steps: in a user device: randomly generating an ephemeral decryption key, transmitting the ephemeral decryption key to a security server, and retrieving a key index from the security server; encrypting an identity information based on a part of the ephemeral decryption key to generate an electronic digital signature and an authentication token; and combining the key index, the electronic digital signature, and the authentication token to form an ephemeral certificate and transmitting the ephemeral certificate to a non-Internet electronic device; and in the non-Internet electronic device: parsing the ephemeral certificate to obtain the key index; and forwarding the key index to the security server via a transport connection including the user device to retrieve the ephemeral decryption key from the security server based on the key index.