Challenges in the Implementation and Simulation for Wireless Side-Channel based on Intentionally Corrupted FCS

We report on the challenges faced in the implementation and simulation of a side-channel communication based on frames with an intentionally corrupted Frame Check Sequence (FCS). Systematically corrupted FCSs can be used to enable covert communications between nodes that share the same algorithm for deciphering the FCS. In order to assess the possibility in detecting this side-channel communication it is necessary to have the ability to simulate it as well as to implement it on actual devices. Nearly all simulators drop corrupted frames before they reach their destination, making it impossible to simulate any side-channel communication based on intentionally corrupted FCS. We present an example of the modifications required to prevent this as applied to a well-known simulator called Sinalgo. We also discuss problems encountered when trying to intentionally corrupt the FCS on actual devices.