Trojan Counteraction in Hardware: A Survey and New Taxonomy

The widespread expansion of the semiconductor industry and various production phases have led to the increased importance of fabricating highly secure chips. Both in factories manufacturing and later at actual operation, digital integrated circuits (IC) might encounter a variety of hardware attacks, one type of which involves Hardware Trojans (HT). Due to their diversity, it has become a major hardware security challenge to prevent, detect and track down HTs. In this regard, the first step is to understand the taxonomy of Trojans and the current ways in which they can be encountered. For that purpose, certain classifications are required. With their downsized dimensions, the Trojans have become extremely difficult to detect, thus promoting the employment of consolidated detection methods. It is, therefore, useful for users to establish an appropriate classification of various Trojans and detection methods. Since the most ideal strategy to tackle the Trojan problem is to understand their taxonomy and counter attack techniques, it seems crucial to establish a classification entailing a wide variety of methods. Therefore, a new classification was proposed in this paper as an ideal user guideline, covering the entire anti-Trojan methods in two categories, i.e. prevention and detection. The users can, at any operating stage whether before or after the HT attack, take an appropriate measure to address the Trojan threat through selecting a correct solution.