Embodiments of a device and method are disclosed. In an embodiment, a Controller Area Network (CAN) device includes a security module connected between a CAN bus interface of a CAN transceiver and a microcontroller communications interface of the CAN transceiver and a shield device connected between the CAN bus interface and the microcontroller communications interface. The security module is configured to perform a security function on data traffic received from the CAN bus interface or from a Serial Peripheral Interface (SPI) interface of the microcontroller communications interface. The shield device is configured to direct CAN Flexible Data-rate (FD) traffic received from the CAN bus interface to the security module.