Vehicle-level versus ECU-level controls

Just as the threat analysis and risk assessment (TARA) is performed at multiple layers of the design, the security controls are applied hierarchically. As a result of this layered analysis, cybersecurity controls are applied in a layered fashion, which is essentially a defense-in-depth cybersecurity strategy. With each security layer, the likelihood of a successful breach is reduced as attackers must defeat or find gaps in multiple security layers before achieving their objective. Figure 8.2 shows 11 security layers applied across the various vehicle life cycles:

Figure 8.2 – Defense-in-depth security layers and controls

Each security layer shown in Figure 8.2, is considered a single cybersecurity control family, which, in turn, relies on several technical controls. In the remainder of this chapter, we will walk through the layers of the vehicle architecture to present common cybersecurity controls that are...