In order to cope with problems related to malicious copying and illegal use of software, security authorization of software with intellectual property rights is an effective means to ensure software security. In the software authorization process, it is particularly important to use a highly secure encryption algorithm for the authorization data. This study proposes a new authorization encryption method, that is, a hybrid encryption algorithm of DPAPI encryption algorithm and RSA digital signature algorithm. This algorithm uses the DPAPI encryption algorithm to encrypt the client’s application for authorization information, while ensuring the encryption and the correctness of the software authorization at the same time, and then uses the RSA digital signature algorithm to digitally sign the server-side authorization information to ensure the unforgeability of the authorization information. The verification of the hybrid encryption algorithm shows that the algorithm has certain feasibility in the software authorization process.