A system provides cryptographic means for securing the transmission of health data from devices of varying processing power and over various network protocols. The system is configured to transmit and receive packets to and from a remote patient monitoring device over multiple types of communication sessions. The system authenticates at least some of the data packet payloads and headers using multiple message authentication codes. The system can, for one type of communication session, the simulate or intercept acknowledgement packets generated for use with another type of communication session.