Simulink/Stateflow is a popular commercial model-based development tool for many industrial domains. For safety and security concerns, verification and testing must be performed on the Simulink/Stateflow designs and the generated code. In this paper, we present an automatic test generation approach for Simulink/Stateflow based on its translation to Input/Output Extended Finite Automata (I/O-EFA) that we have developed in our prior works. The test generation problem requires identifying the executable paths of the I/O-EFA model and also generating a test input for those paths. Note in order to execute a path, a certain sequence of other paths must be executed first, which we automatically identify. The approach is implemented by applying two different techniques, model checking and constraint solving. Both test generation implementations are validated by a case study. The results show that both implementations can generate test cases as expected and the implementation based on constraint solving is in general faster.

Channel state information (CSI) has been recently shown to be useful in performing security attacks in public WiFi environments. By analyzing how CSI is affected by finger motions, CSI-based attacks can effectively reconstruct text-based passwords and locking patterns. This paper presents WiGuard, a novel system to protect sensitive on-screen input information in a public place. Our approach carefully exploits WiFi channel interference to introduce noise to attacker’s CSI measurements to reduce the success rate of CSI-based attacks. Our approach automatically detects when a CSI-based attack happens. We evaluate our approach by applying it to protect text-based passwords and pattern locks on mobile devices. Experimental results show that our approach is able to reduce the success rate of CSI-based attacks from 92–42% for text-based passwords and from 82–22% for pattern lock.

Process-level virtual machine (PVM) based code obfuscation is a viable means for protecting software against runtime code tampering and unauthorized code reverse engineering. PVM-based approaches rely on a VM to determine how instructions of the protected code region are scheduled and executed. Therefore, it is crucial to protect the VM against runtime code tampering that alters the instructions and behavior of the VM. This paper presents VMGuards, a novel PVM-based code protection system that puts the security of VM as the first class design concern. Our approach advances prior work by promoting security of the VM as the first class design constraint. We achieve this by introducing two new instruction sets to protect the internal implementations of critical code segments and the host runtime environment where the VM runs in. Our new instruction sets not only have an identical code structure as standard virtual instructions, but also provide additional information to allow the VM to check whether the critical internal implementation or the runtime environment is affected. We evaluate our approach by using a set of real-life applications. Experimental results show that our approach provides stronger and more fine-grained protection when compared to the state-of-the-art with little extra overhead.