PROPOSTE DI TESI e/o STAGE

Master thesis on Virtual Private Mobile Networks For Location Privacy

 
Immagine Tomasin Stefano
Master thesis on Virtual Private Mobile Networks For Location Privacy
di Tomasin Stefano - giovedì, 19 agosto 2021, 15:16
 
Our position and movements reveal many sensitive information, including our acquaintances, health conditions, work, lifestyle, and buyer preferences. Recently, the localization of smartphones has been considered for contact-tracing in the fight against the COVID-19 outbreak. In this occasion, the privacy of position and movement information was widely debated, and solutions based on ranging rather than positioning were widely adopted, still raising various privacy concerns.

img2.png

In 5G cellular systems, the user position is explicitly known by the network in precision of decimeters and passed also to external applications. Moreover, the transmission of unencrypted control signals by the smartphone allows an eavesdropper to know and track the user position. In cases, a virtual private mobility network (VPMN) could be deployed to ensure privacy.

The concept of VPMN is similar to the conventional virtual private network (VPN) used at the network layer to obtain a private sub-network over the Internet. The VPMN operates across all the communication layers, as it provides that UEs directly communicate among themselves and mutually operate as relays with the cellular networks. Therefore, a message departing from UE-A first directly goes to UE-B (without involving the cellular network) and then it is forwarded to the gNB by UE-B on behalf of UE-A. In this way, transmission of the message from UE-A occurs from UE-B, whose position may be revealed to external eavesdroppers. For Example, consider that VPMN wants to conceal being within a building. By using the VPMN, it first establishes a VPMN connection with UE-B, a device that is in its proximity, but outside of the building. UE-A then exchanges all messages with the cellular network usingUE-B as a proxy, which that has the position information on UE-B.Note that the VPMN does not need a single point of attachment to the cellular network, i.e., all UEs of the VPMN can communicate (in uplink) with the cellular network. The key point is that the transmitting UEdoes not reveal the position from which a message is originated. This is achieved for example by randomly choosing the UE that forwards (in uplink) the packetto the cellular network. For downlink transmission, the cellular network will do an anycast transmission to theVPMN UEs, which will then route the packet to the correct destination UE.

The thesis can proceed in various directions:

- the evaluation of the VPMN ability to hide the location (probability of finding users around, in specific directions, location uncertainty at the base station…);

- the additional costs of delay incurred by packets doing multiple hops, and additional power consumption of collaborating nodes;

- the discovery of nearby nodes and the determination of the routing path
the design of beamforming in order to direct signal towards other nodes of the VPMN, without leaking information to the base station.

Thesis suited for students of ICT for Internet and Multimedia and Computer Science

For further information, contact Prof. Stefano Tomasin (stefano.tomasin@unipd.it)