Systems, devices, and methods are provided that allow the authentication of devices within analyte monitoring systems. The analyte monitoring systems can be in vivo systems and can include a sensor control device with a sensor and accompanying circuitry, as well as a reader device for communicating with the sensor control device. The analyte monitoring systems can interface with a trusted computer system located at a remote site. Numerous techniques of authentication are disclosed that can enable the detection of counterfeit components, such as a counterfeit sensor control device.