Masking is a widely used countermeasure against Side-Channel Attacks, nonetheless, the implementation of these countermeasures is challenging. Experimental security evaluation requires special equipment, a considerable amount of time, and extensive technical knowledge. Therefore, to automate and to speed up this process, a formal verification can be performed to asses the security of a design. In this work we present VerMI, a verification tool in the form of a logic simulator that checks the properties defined in Threshold Implementations to address the security of a hardware implementation for meaningful orders of security. The tool is designed so that any masking scheme can be evaluated. It accepts combinational and sequential logic and is able to analyze an entire cipher in short time. With the tool we have managed to spot a flaw in the round-based KECCAK implementation by Gross et al., published in DSD 2017.
