TLPKA: Pairwise Key Agreement Based on the Geometrical Property of the Tangent Line in Ad Hoc Network Systems

In this paper, we propose a new pairwise key agreement, TLPKA (Tangent Line Pairwise Key Agreement), for establishing a secure link between members in an ad hoc network. With pairwise keys, data transmitted in ad hoc networks can be protected from the eavesdropping of outsiders. These pairwise keys can also be used to authenticate members in ad hoc networks. In addition, due to the property of uniqueness of pairwise keys, it also provides non-repudiation for data transmitting. In our scheme, we propose a new idea for the design of pairwise key agreements in an ad hoc network. Our scheme is based on the geometrical property of the tangent line and the mechanisms in our scheme are inspired by the Shamir secret sharing scheme. Our schemes also provide reciprocal authentication among node communicants. The robustness of our scheme is based on the DH problem and the indefinite solutions in coordinate geometry. In addition, we compare our scheme with other schemes. Although there is a higher overhead associated with our scheme, it maintains a higher security level than the other schemes.