A user device implements a certificate authority for issuing digital certificates that extend to other computing devices a level of trust to a particular user paired with the user device. The user device may obtain user persona information, generate a user key, and combine the user key with a device key for the generation of a digital certificate. The computing device may further transmit the digital certificate to a certificate management system, which manages interactions between other computing devices and the user device or authorizes operation of other computing devices by the particular user based on the digital certificate.