Blockchain incentivized data forwarding in MANETs: Strategies and challenges

Recently, blockchain trustless properties started to be investigated to design cooperation enforcement mechanisms in many systems. This paper presents a comprehensive and detailed review of works on blockchain-enabled data forwarding incentives for multi-hop MANETs. We contextualize the problem of selfish misbehavior in networks composed of routers that are property of different participants: community, D2D, and vehicular networks, including DTN alternatives. We discuss how uncooperative behavior from multiple device owners leads to unreliable communication affecting trust in MANETs. We summarize pre-blockchain incentive mechanisms for data forwarding, classified as credit-based and reputation-based, and outline game-theoretic approaches. We discuss blockchain features useful for data forwarding incentives in multi-hop MANETs, detailing off-chain mechanisms that have been applied in the state-of-the-art. We describe the critical points in the state-of-the-art based on research papers, patents, and products. Finally, we discuss and summarize existing strategies and challenges for further research.