## 6 Architectures Comparison
### Security Comparison
#### 6.4.2 Security Analysis of [PERSON] et al. [28] Architecture  
Table 7 shows the threats detected in the [PERSON] et al. [28] architecture, with the greatest number of them relying on very low or medium threats, according to the typical analysis. 1. **Very Low Risk Threats:** We concluded that 96 (31.9%) of all of the threats fitted into this level of risk. By looking at the percentage distribution of each type of threat within each risk category, it is noticeable how evenly they are all distributed. The lowest value is 26.7% and the highest is 37.5%, corresponding to spoofing and elevation of privilege, and information disclosure, respectively. The latter concerns privacy risks associated with violation of confidentiality, thus does not carry a high risk for the safety or operability of the ACN. Other threats such as tampering or denial of service, \begin{table}
\begin{tabular}{l l l l l} \hline \hline
**Threat** & **Very Low** & **Low** & **Medium** & **High** \\ \hline Information Disclosure & 33 (38.8\%) & 15 (17.6\%) & 34 (40\%) & 3 (3.5\%) \\ \hline Tampering & 24 (28.2\%) & 25 (29.4\%) & 21 (24.7\%) & 15 (17.6\%) \\ \hline DoS & 26 (30.2.5\%) & 24 (27.9\%) & 21 (24.4\%) & 15 (17.4\%) \\ \hline Repudiation & 5 (33.3\%) & 0 (0\%) & 5 (33.3\%) & 5 (33.3\%) \\ \hline Spoofing & 4 (26.7\%) & 3 (20\%) & 6 (40\%) & 2 (13.3\%) \\ \hline Elevation of Privilege & 4 (26.7\%) & 1 (6.7\%) & 5 (33.3\%) & 5 (33.3\%) \\ \hline \hline \end{tabular}
\end{table} 
Table 7: Security analysis of [PERSON] et al. architecture. The ratio of the number of current risk levels of that category to the total number of threats related to that category is given in parentheses. whose risk is usually high, fall within this region because they are associated with non-critical components, for which the vehicle behavior is not compromised, like sound or pulse sensors. Lastly, for spoofing or elevation of privilege, these percentage values are once again associated with low-importance sensors, which will not impact the ACN considerably. 2. **Low-Risk Threats**: We conclude that the paper has 68 low-risk threats in total (22.6%). We noticed that there are no repudiation threats associated with a low risk level, with them being concentrated more on the medium and high levels. The same logic applies to the low level of spoofing and elevation of privilege threats. Although there are fifteen threats present, these represent only 17% of the total information disclosure threats. This is mainly because information disclosure of extremely sensitive private data falls under a higher level of risk. For example, when the information disclosed relates to the gyroscope, cloud, or accelerometer, it can relate to a low risk level as it does not allow attacker to interfere with the ACN functionality. About 27.3% of denial of service attacks are categorized as low risk level. This is mainly because certain components being out of commission by a denial of service does not directly affect the functioning of the overall ACN system, for example, the gyroscope, cloud, and OBD. Lastly, the highest percentage of overall threats present in the low level of risk are related to tampering. This is mainly because there are many components, whose tampering does not affect the overall functionality of the system, similarly to denial of service. 3. **Medium-Risk Threats**: Through the analysis we found that 92 (30.6%) of the threats belong to this category. It is important to note that for each type of threat the percentage of medium threats is near 25%, which means that at least a quarter of the threats are medium risk level. When we talk about the automotive scenario and ACN functionality it is more likely that all threats will not have a very high impact, but also not a low impact. So, the rest of the threats will be split among the others risk levels. Looking into each percentage, we see that denial of service is the lowest, which is expected because normally this threat will represent a high level of risk. Finally, spoofing has the highest percentage here.