02107nas a2200181   4500000000100000008004100001260001200042653002300054100001700077700002000094700002800114245009900142856005300241300001000294490000700304520160000311022001401911       2018                            d  c06/201810acommunity networks1 aAxel Neumann1 aLeandro Navarro1 aLlorenç Cerdà-Alabern00aEnabling individually entrusted routing security for open and decentralized community networks  uhttp://people.ac.upc.edu/leandro/pubs/semtor.pdf  a20-420 v793 aAbstract Routing in open and decentralized networks relies on cooperation. However, the participation of unknown nodes and node administrators pursuing heterogeneous trust and security goals is a challenge. Community-mesh networks are good examples of such environments due to their open structure, decentralized management, and ownership. As a result, existing community networks are vulnerable to various attacks and are seriously challenged by the obligation to find consensus on the trustability of participants within an increasing user size and diversity. We propose a practical and novel solution enabling a secured but decentralized trust management. This work presents the design and analysis of securely-entrusted multi-topology routing (SEMTOR), a set of routing-protocol mechanisms that enable the cryptographically secured negotiation and establishment of concurrent and individually trusted routing topologies for infrastructure-less networks without relying on any central management. The proposed mechanisms have been implemented, tested, and evaluated for their correctness and performance to exclude non-trusted nodes from the network. Respective safety and liveness properties that are guaranteed by our protocol have been identified and proven with formal reasoning. Benchmarking results, based on our implementation as part of the BMX7 routing protocol and tested on real and minimal (OpenWRT, 10 Euro) routers, qualify the behaviour, performance, and scalability of our approach, supporting networks with hundreds of nodes despite the use of strong asymmetric cryptography.  a1570-8705