An overlay approach to data security in ad-hoc networks

While it has been argued that application-layer overlay protocols can enhance services in mobile ad-hoc networks, hardly any empirical data is available on the throughput and delay performance achievable in this fashion. This paper presents performance measurements of an application-layer overlay approach that ensures integrity and confidentiality of application data in an ad-hoc environment. A key management and encryption scheme, called neighborhood key method, is presented where each node shares secrets only with authenticated neighbors in the ad-hoc network, thus avoiding global re-keying operations. All proposed solutions have been implemented and empirically evaluated in an existing software system for application-layer overlay networking. Results from indoor and outdoor measurement experiments with mobile handheld devices provide insight into the performance and overhead of overlay networking and application-layer security services in ad-hoc networks.