The invention is applicable to the technical field of a set-top box, and provides a middleware authentication method and a middleware authentication device. The method comprises the following steps of: using a private key to encrypt a license hardware identification range to obtain an encryption identification; respectively implanting the encryption identification and a public key into middleware, wherein the public key and the private key are a pair of digital signatures; during the operation, using the public key to decrypt the encryption identification to obtain the license hardware identification range; reading the hardware identification through an API (application program interface) of a porting layer; judging whether the hardware identification is in the license hardware identification range or not; and if so, obtaining the authentication. The method and the device have the advantages that the private key is used for encrypting the license hardware identification range; the public key is used for decrypting the license hardware identification range; and the security of the whole authentication is enhanced through the asymmetric encryption in the whole process.