# Privacy-Aware Access Protocols for MEC Applications in 5G +
## 3 Statement of the Problem
### Privacy Requirements
#### 3.3.2 Privacy Requirements for Dependent Parties
As pointed out earlier, other MEC applications, which are assumed to be honest but curious, could cooperate with MNO, MEC, or APPIFY. The collaboration could be helpful for gathering extra information about [PERSON] or APPIFY, e.g., when [PERSON] is using another MEC application in parallel to using APPIFY. However, collaboration with other MEC applications would not make any privacy requirements non-applicable. Combination 1: MNO, MEC, and APPIFY Are Dependent  
Assume that MNO deploys its own MEC host to the network. Additionally, MNO has a mobile application for its subscribers. All three parties share information related to users with each other. As explained above, we assume that neither Alice nor APPIFY collaborates with other users or applications. The messages of Alice pass through MNO and MEC to APPIFY. None of the privacy requirements--except those for outsiders--are applicable when all the parties are dependent because MNO, MEC, and APPIFY can learn and share information \begin{table}
\begin{tabular}{|c|c|c|c|c|} \hline  & \multicolumn{4}{c|}{**Dependency Combinations**} \\ \hline
**Requirements** & **NONE** & **ALL** & **MNO** & **MEC** & **MNO** \\  & & & **\&MEC** & **\&APP** & **\&APP** \\ \hline R1-MNO-D & \(\mathcal{O}\) & N/A & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R2-MNO-D & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) & - \\ \hline R3-MNO-I & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) & - \\ \hline R4-MNO-U & \(\mathcal{O}\) & N/A & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R5-MNO-U & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R6-MEC-D & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R7-MEC-I & \(\mathcal{O}\) & N/A & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R8-MEC-I & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) \\ \hline R9-MEC-U & \(\mathcal{O}\) & N/A & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R10-MEC-U & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) \\ \hline R11-APP-D & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) & - \\ \hline R12-APP-I & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) & - \\ \hline R13-APP-U & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) & - \\ \hline R14-APP-U & \(\mathcal{O}\) & N/A & \(\mathcal{O}\) & \(\mathcal{O}\) & - \\ \hline R15-OUT-D & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R16-OUT-D & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R17-OUT-I & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R18-OUT-I & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R19-OUT-U & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline R20-OUT-U & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) & \(\mathcal{O}\) \\ \hline \end{tabular}
\end{table} 
Table 1: Effect of dependency combinations on applicability of the privacy requirements and how the solution fulfills them. about [PERSON] from these messages, e.g., her identities, the services she uses, the content of the messages. This combination is shown in Table 1, in the column under the heading 'ALL'. MNO deploys its own MEC host, called MNO-MEC, to the network. In this combination, APPIFY is independent, and it shares information neither with MNO nor with MNO-MEC. The MNO and MNO-MEC are dependent parties, so they share information with each other. Due to our assumption above, there is no collaboration neither between Alice and the other users nor between APPIFY and the other applications. Therefore, some of the requirements become not applicable because MNO and MNO-MEC share information and can associate it with the information they have.