# Trustworthiness of Situational Awareness: Significance and Quantification
## 5 Numerical Results
### Case 2: Low-Trust Information Source
Using Equation (1), the trustworthiness score of the MS \(\mathcal{T}_{MS}\) can be determined as \(\mathcal{T}_{MS}=(0.125)(0.3)+(0.125)(0.2)+(0.125)(0)+(0.125)(1)+(0.125)(1)+(0.1 25)(1)+(0.125)(1)=0.5625\). **Cluster Head Node:** Here, we calculate the trustworthiness of the CHN based on Equation (3). In the following, we calculate the score of various metrics that affect the trustworthiness of a node. _Confidentiality:_ In this case, the plaintext information from the MS is relayed by the CHN to the GN. The message itself is stored in private in the CHN, and is not accessible to unauthorized parties, and thus a confidentiality score equal to 0.3 can be assigned to the CHN. _Integrity:_ The messages obtained from the MS are stored in ECC memory in the CHN, but no HMAC is calculated at the CHN, and thus an integrity score of 0.2 can be ascribed to CHN. _Authenticity:_ The CHN can be successfully authenticated (with an authentication protocol), and thus an authenticity score of 1 can be attributed to the CHN. _Availability:_ With the assumption that the CHN is responsive to the authentication messages and is available, its availability score can be assigned as 1. Since, in our model, there are four metrics that influence the trustability of the node, we assign a weight of \(1/4=0.25\) to each metric, although different weights can be assigned to different metrics depending on the mission needs. Using Equation (3), the trustworthiness score of the CHN \(\mathcal{T}_{CHN}\) can be determined as \(\mathcal{T}_{CHN}=(0.25)(0.3)+(0.25)(0.2)+(0.25)(1)+(0.25)(1)=0.625\). **Gateway Node:** The trustworthiness of the GN can be calculated similarly to that for the CHN based on Equation (3), and can be given as \(\mathcal{T}_{GN}=(0.25)(0.3)+(0.25)(0.2)+(0.25)(1)+(0.25)(1)=0.625\). **Router Node:** The trustworthiness of the RN can be calculated similarly to that for the CHN based on Equation (3), and can be given as \(\mathcal{T}_{RN}=(0.25)(0.3)+(0.25)(0.2)+(0.25)(1)+(0.25)(1)=0.625\). **Data Fusion Node:** The trustworthiness of the DFN can be calculated similarly to that for the CHN based on Equation (3), and can be given as \(\mathcal{T}_{DFN}=(0.25)(0.3)+(0.25)(0.2)+(0.25)(1)+(0.25)(1)=0.625\). **Link \(\boldsymbol{l_{1}}\) or \(\boldsymbol{l_{MS-CHN}}\):** Here, we calculate the trustworthiness of the wireless link between the MS and the CHN based on Equation (4) of our proposed model (Section 4.1). In the following, we calculate the score of various metrics (i.e., confidentiality, integrity, availability, and quality) stipulated in Equation (4) that affect the trustworthiness of a link. _Confidentiality:_ Since the MS sends the information in plaintext (i.e., without encryption) to the CHN over the wireless link, the confidentiality score for \(l_{1}\) or \(l_{MS-CHN}\) can be assigned as 0. _Integrity:_ Since no hash (or HMAC) of the message is transmitted from the MS and the CHN in this case, the integrity score for \(l_{1}\) can be ascribed as 0. _Availability:_ Assuming that the wireless link between the MS and the CHN can carry the messages and is not overloaded with data traffic nor is affected by any denial-of-service attack, an availability score of 1 can be attributed to \(l_{1}\). _Quality:_ Here, the quality of a link can be referred to as its bit error rate. Assuming a bit error rate of \(5\times 10^{-3}\)[19], the quality score for \(l_{1}\) can be calculated as \(1-0.005=0.995\). Since, in our model, there are four metrics that influence the trustability of a link, we assign a weight of 0.25 (i.e., \(1/4=0.25\)) to each metric, although different weights can be assigned depending on mission needs. Using Equation (4), the trustworthiness score of the link \(l_{1}\) or \(l_{MS-CHN}\) can be determined as \(\mathcal{T}_{l_{1}}=(0.25)(0)+(0.25)(0)+(0.25)(1)+(0.25)(0.995)=0.49875\). **Link \(l_{2}\) or \(l_{CHN-GN}\):** Here, we calculate the trustworthiness of the wired link \(l_{2}\) or \(l_{CHN-GN}\) between the CHN and the GN that connects the CHN to the core network based on Equation (4).