Fully Distributed Public Key Management through Digital Signature Chains for Delay and Disrupt Tolerant Networks

Security solutions are not easily adapted to the DTN paradigm, for example, traditional key management solutions cannot be applied in such environments. A key management scheme for DTNs must consider the dynamic topology, be self-organized and distributed and be effective in the presence of intermittent connections. There are just a few key management scheme for DTNs. Nevertheless, all of them have serious issues. They generate a huge overhead, have a single point of failure, are centralized or do not provide any security against very simple attacks. This work introduces a new key management scheme for DTNs based on chains of digital signatures (DSC-KM - Digital Signature Chains Key Management Scheme). It is decentralized, fully distributed, and does not have a single point of failure. It allows nodes to leave and joint the network at any time, works in the presence of intermittent connections, has a very small communication and memory overhead. It is based on chains of digital signatures and on a very simple chain exchange mechanism. According to simulation results, it is able to correctly and securely disseminate all certificates through the network in a short period, while maintaining the size of the chains very small. Moreover, it is able to resist to several attacks to the key management infrastructure.