# Privacy-Aware Access Protocols for MEC Applications in 5G +
## 3 Statement of the Problem
### Privacy Requirements  
The system model in Section 3.1 includes the user [PERSON] and outsiders, and on the other hand, MNO, MEC, and APPIFY, which together serve the user. The data seen by MNO, MEC, and APPIFY include the necessary information to provide the service to [PERSON]. Outsiders do not participate in the protocol.  
The security properties of data confidentiality, identity confidentiality, and unlinkability were taken into account when defining privacy requirements for the serving parties: MNO, MEC, and APPIFY, and the outsiders.  
Below, we labeled by \"D\" the requirements related to data confidentiality. These requirements aim to prevent the party from accessing information that it does not need to know.  
The requirements related to identity confidentiality are labeled by \"I\" below. [PERSON] may have several identities for different parties in the system model. The goal of these requirements is to prevent the discovery of identities of the user by parties that do not need them. One party should not know the identities that [PERSON] uses with other parties.  
Below, we have labeled by \"U\" the requirements related to unlinkability. The goal of these requirements is to prevent distinguishing whether two messages belong to the same user, same destination, or include the same identifier.  
The list of privacy requirements is given next.  
* MNO should not learn which MEC application [PERSON] is using.
* MNO should not learn the content of what [PERSON] sends to and receives from APPIFY.
* MNO should not learn that Alice13 is the identifier of [PERSON] for APPIFY.
* MNO should not be able to distinguish whether two messages are related to the same user identifier for the MEC application.
* MEC should not learn the content that [PERSON] sends to and receives from APPIFY.
* MEC should not learn that identifiers \"Alice\" or IMSI are relevant to the messages.
* MEC should not learn that identifier Alice13 is relevant to the messages.
* MEC should not be able to distinguish whether two messages are related to the same person or the same IMSI.
* MEC should not be able to distinguish whether two messages are related to the same user identifier for a MEC application.
* APPIFY should not learn anything related to [PERSON] in addition to what can be deduced from information that [PERSON] provides while communicating with APPIFY.
* APPIFY should not learn that \"Alice\" or IMSI is related to Alice13.
* APPIFY should not distinguish whether two messages are coming from the same device.
* APPIFY should not distinguish whether two messages are related to the same IMSI.
* Outsiders should not learn which MEC application [PERSON] is using.
* Outsiders should not learn the content of what [PERSON] sends and receives.
* Outsiders should not learn that the identifiers \"Alice\" or IMSI are relevant to [PERSON].
* Outsiders should not learn that identifier Alice13 is relevant to [PERSON].
* Outsiders should not be able to distinguish whether two messages are related to the same MEC application.
* Outsiders should not be able to distinguish whether two messages are related to the same user identifier.