Public key distribution scheme for delay tolerant networks based on two-channel cryptography

A delay tolerant network (DTN) is a store carry and forward network characterized by highly mobile nodes, intermittent connectivity with frequent disruptions, limited radio range and physical obstructions. Emerging applications of DTN include rural DTN, vehicular DTN and pocket DTN. The development of DTN raises a number of security-related challenges due to inconsistent network access and unreliable end-to-end network path. One of the challenges is initial secure context establishment as it is unrealistic to assume that public key infrastructure (PKI) is always globally present and available, hence, the public key management becomes an open problem for DTN. In this paper, for the first time, we propose a dynamic virtual digraph (DVD) model for public key distribution study by extending graph theory and then present a public key distribution scheme for pocket DTN based on two-channel cryptography. By distinguishing between owners and carriers, public key exchange and authentication issues in the decentralized pocket DTN environment can be solved by a two-channel cryptography process and our simulation results have proven it.