Modeling and Analysis of Thermal Covert Channel Attacks in Many-core Systems

In a many-core chip, thermal flux and thermal correlation among the cores can be explored to create a thermal covert channel (TCC). In this paper, we provide an analytical model to quickly determine the key TCC performance metrics, in terms of bit error rate (BER), signal to noise ratio (SNR), and channel capacity, without going through lengthy computer simulation and/or physical experiments that are normally needed in current TCC performance studies. According to our model, the TCCs BER is proportional to the square root of the transmission frequency, which can be explored quantitatively to boost the TCCs transmission efficiency by letting the TCCs thermal signal be transmitted at a higher frequency. In addition, our proposed model also links the jamming noise and application of Dynamic Voltage Frequency Scaling (DVFS) to TCCs BER performance, a feature that can be explored to design/optimize the countermeasures against the TCC attacks. The TCC performance predicted by the proposed theoretical model is found in a good agreement with that obtained from computer simulations, with an average error lower than 7%.