Neutralizing a design-for-hardware-trust technique

Hardware Trojan horses (HTHs) are important threats to the trustworthiness of hardware chips. Design-for-hardware-trust (DFHT) techniques are used to enhance the detectability of possible HTHs. Existing DFHT approaches are usually ad-hoc techniques. This characteristic makes them vulnerable to neutralization efforts. We study this concept by focusing on an effective available DFHT technique, namely dummy scan flip-flop (DSFF) insertion. We provide a method for neutralizing the DSFF technique. Our experiments show that DSFF can be easily neutralized without recognizable side effects. This demonstrates the importance of improving the existing ad-hoc DFHT techniques.