Layered and Service-Dependent Security in CSMA/CA and Slotted Vanets

The implications and challenges of security in vehicular ad-hoc networks are huge for several reasons and, basically, for human safety effects and due to the complex and highly dynamic setting. Additionally security, being a cross-layer topic, can be managed at different layers of the network stack (e.g. at MAC-level - with encryption and authentication, at network-layer - as with IPsec, at transport-layer TLS, SSL). A rich scientific literature has addressed the issue of vanet security, however, all the proposed solutions (i) focus on a specific layer and (ii) offer either robust but not scalable solutions (such as the PKI infrastructure, hardly managed under mobility for all the nodes and services) or weak ones (at least weak if applied to human safety). For this reason, in the present paper, security for vanet is faced with a layered approach which lets envisage several solutions, properly and hierarchically differentiated for distinct services. Additionally, what introduces an even stronger novelty, the dissertation covers both CSMA/CA and slotted MAC protocols, having the latter recently encountered a certain scientific favour.