List the potential threats when an attacker in the supply chain performs scan-based attacks. 1. List three scan-based noninvasive attacks. 2. Explain the purpose of placing the Shadow chain into the...

List the potential threats when an attacker in the supply chain performs scan-based attacks.

1. List three scan-based noninvasive attacks.

2. Explain the purpose of placing the Shadow chain into the dynamically obfuscated scan (DOS) architecture.

3. How to choose the number of dFFs inserted in the scan chain? Explain.

4. Introduce a few more scan-based attacks countermeasures besides which are discussed in this chapter.