Daeseon Choi, Seunghun Jin and Hyunsoo Yoon
"ETRI, KAIST"
email: sunchoi@etri.re.kr
As there is no central authority or fixed infrastructure in mobile ad hoc network, key management should be performed by the nodes themselves in a self organizing manner, which means that each distributed peer nodes perform the role of authority. To be ``fully'' self organized key management, there must be no dependency of any infrastructure, any central server, any secret share dealer and any initial trust relationship between nodes even from the initial boot strapping stage. And transitivity of trust must be minimized. In this paper we propose a fully self organized public key management scheme supporting all those requirements and limitations. In this method, all peer node can issue public key certificate of other node.
Certificate is issued after authenticating physical entity when two peer nodes encounter physically. Using secure side channel in limited range, passive attack is protected. What makes it possible is mobility of node itself. Trustworthiness of issuer of the certificate is evaluated by replying party. As there's no priori trust, trustworthiness of the issuer is evaluated from reputation of the issuer by other nodes. Reputation reflects other node's experience about the issuer. Gathered reputation reflects trustworthiness of the issuer in the whole network. So it's possible to decide trustworthiness without any priori trust.