A system and method for confirming identity and authority by a patient medical device is provided. Master credentials are issued to a requesting device and a receiving device from an authorizing agent. The master credentials include the authorizing agent's public key and a digital signature of a root certification authority. Device credentials are issued to the requesting device from the authorizing agent. The device credentials include the requesting device's public key and the authorizing agent's digital, signature. Identification credentials are provided to the receiving device and include the device credentials and the requesting device's digital signature. The requesting device is authenticated. The authorizing agent's digital signature in the device credentials is checked using the authorizing agent's public key in the master credentials of the receiving device. The requesting device's digital signature in the identification credentials is checked using the requesting device's public key in the device credentials.