Dynamic search tolerance at runtime for lookup determinism in the DHT-based P2P network Kad

For the realization of decentralized communication infrastructures, P2P technology offers an excellent technological foundation to complement or replace existing centralized structures, which take the client-server network model as a basis. In particular, the distributed hash table-based P2P network Kad impresses with high lookup performance, scalability, and resilience against failures and attacks. In addition to these advantages, the Kad protocol needs an extension in terms of its lookup to allow for lookup determinism in an a priori unknown Kad network. Therefore, this paper introduces a dynamic search tolerance, which adapts itself to any network configuration autonomously at runtime. The search tolerance is periodically calculated and all nodes are provided with the updated value. Thereby, the Kad protocol meets the demands for deterministic lookups, which enables dependable and efficient data retrieval, qualifying it as reliable basis of communication infrastructures in, e.g., real-time environments. Results show the high performance of the proposed algorithms for a Kad network with up to 50,000 nodes.