A method of registering network devices in a digital rights management system (DRMS) includes receiving a digital certificate transmitted by the network device requesting registration and verifying the validity of the certificate. The DRMS may then send cryptographic information to the applying network device. The network device may be authorized for registration via a user interface to the DRMS. The DRMS may conduct a proximity test to determine of the network device is proximate to the DRMS. If the certificate is validated, authorization is received, and the proximity test indicates that the network device is proximate to the DRMS, the network device may be registered. A registered network device is then authorized to play protected digital content.