The invention provides a cross-domain
authentication method based on a block chain
certificate, and the method comprises the steps that: in a first stage, an entity in a trust domain transmits the own block chain
certificate in a cross-domain manner; in a second stage, a block chain
proxy server where the entity is located verifies the block chain
certificate of a cross-domain block chain
proxy server through a block chain; and, in a third stage, after the cross-domain identity
authentication is successful, the cross-domain block chain
proxy server generates a new cross-domain block chain certificate. The cross-domain block chain certificate is generated, so that the identity
authentication efficiency can be improved when the same cross-domain identity authentication operation is performed next time. Each trust domain is provided with a private
key generation center to perform unified management on all signature private keys in the domain. The block chain certificate adopts a lightweight structure. On the premise of ensuring the security, the problem of low efficiency in traditional cross-domain identity authentication is solved. In addition, the traditional digital certificate is subjected to lightweight improvement to meet the current requirement, and the communication overhead is further reduced.