# On Blockchain-Enhanced Secure Data Storage and Sharing in Vehicular Edge Computing Networks
## 3 Proposed Architecture
### Procedures of Proposed Scheme
#### 3.3.2 Message Broadcasting, Rating Generation, and Uploading  
Later, \(V_{i}\) downloads the latest data from LSSC (local data storage of edge node) of nearby RSU on the system initialization step. Then, the sending vehicle \(V_{s}\) collects the message information \((Msg_{s})\) using its sensing devices and broadcasts the message encrypted \((E_{n}Msg_{l,s}^{p})\) to the network with a specific time \(i\) and location \(p\). LSSC, as an RSU  
\begin{table}
\begin{tabular}{l l} \hline \hline
**Symbol** & **Description** \\ \hline \(V_{i}\) & The \(i\)th vehicle in the network \\ \hline TA & The trusted authority for vehicle registration \\ \hline \(ID_{i}\) & The \(i\)th identity of vehicle \\ \hline \(PK_{l}D_{s}SK_{l}D\) & Public and private key pair of vehicle \\ \hline \(Cert_{l}D\) & The corresponding certificate of vehicle \\ \hline \(V_{s}\) & The sending vehicle which collect and broadcast the information message \\ \hline \(E_{n}Msg_{l,s}^{p}\) & The message encrypted by \(V_{s}\) with a specific time \(i\) and location \(p\) \\ \hline \(V_{r}\) & The receiving vehicle (the neighboring vehicle) which generate the rating \\  & of message \\ \hline \(cb_{Msg_{r}^{p}}\) & The credibility of the message \\ \hline \(R_{Msg}^{s,r}\) & The message rating uploaded by \(V_{r}\) \\ \hline \(\delta_{s}^{j,p}\) & The trust value rating aggregated by RSU \\ \hline \(Block_{data}\) & The candidate for a new block on the process of consensus mechanism \\ \hline \hline \end{tabular}
\end{table}
Table 2: Summary of notations.  
Figure 2: Procedures of proposed architecture.  
local data storage, collects the broadcasted data from \(V_{s}\). On the other hand, the neighboring vehicles, as the receiving vehicles \((V_{r})\), classify all message into groups \((M_{1}^{1},M_{7}^{2},...M_{1}^{p},...)\), then calculate and aggregate the credibility of the message \((cb_{Msg_{i,r}^{p}})\) based on Equation (1) as follows.  
\[cb_{Msg_{i,r}^{p}}=\alpha+E_{n}Msg_{i,s}^{p-\beta d_{m}} \tag{1}\]  
where \(E_{n}Msg_{i,s}^{p}\) is an encrypted information message of \(V_{s}\) that contains several related information, \(E_{n}Msg_{i,s}^{p}=(Msg_{s}||timestamp||location)\). Both \(\alpha\) and \(\beta\) are predefine parameters, in which \(\alpha\) represents the lower bound of message rating, whereas \(\beta\) is a parameter that controls the rate of message credibility [8] based on \(d_{m}\). Here, \(d_{m}\) is the distance between \(V_{i}\) and event location of \(E_{n}Msg_{i,s}^{p}\). Using Equation (1), \(V_{r}\) obtains a credibility set \(C_{s}^{i,p}\) for \(Msg_{s}\), where \(C_{s}^{i,p}=(cb_{s1,r}^{i,p}cb_{s2,r}^{i,p}cb_{s3,r}^{i,p}\ldotscb_{s,r}^{i,p})\). \(cb_{s,r}^{i,p}\) represents the credibility message of \(V_{s}\), which is assessed by \(V_{r}\). Correct messages generate a positive rating (+1); otherwise, a negative rating (\(-1\)). Next, \(V_{r}\) uploads the message rating \((R_{Msg}^{s,r})\) of \(V_{s}\) to nearby a RSU using the format \(R_{Msg}^{s,r}=(V_{s},V_{r},E_{n}Msg_{i,s}^{p},rating)\).