Abstract: A communication device such as a cellphone or tablet may be configured to allow individual components to be selectively disabled, using for example, airgap switches. When the component is re-enabled a security check is performed to confirm that the component was not altered prior to continuing full operation of the device. The security check may include running a checksum over the component's firmware, comparing a hash of the firmware to an expected value, and checking a digital signature of the firmware.

Abstract: A cellular communication device uses manually operated airgap switches that selectively enable or disable various functions of the communication device. The airgap switches physically disconnect conductors associated with power or signal transmission so that the operator is assured that the disabled function is not vulnerable to software-based intrusions. The various functions may include GPS, NFC, Bluetooth, WiFi, and cellular wireless devices. The functions may also include transducers such as a camera or microphone. In other cases, the disabled functions may include sensors such as an accelerometer, gyroscope, or compass that may be used to create a dead-reckoning trail.