Identity authentication method and device

Disclosed are an identity authentication method and device that are applied to a network function virtualization (NFV) system and can adapt to the dynamic change of the system. The NFV system comprises a virtual network function (VNF). The VNF comprises a first virtual network function component (VNFC) and a second VNFC. The authentication method comprises: generating a public key and a private key of a first VNFC and a public key and a private key of a second VNFC; writing or sending the private key of the first VNFC and the public key of the second VNFC into or to the first VNFC; and writing or sending the public key of the first VNFC and the private key of the second VNFC into or to the second VNFC, the public key and the private key of the first VNFC and the public key and the private key of the second VNFC being used for identity authentication of the first VNFC and the second VNFC.