B-Smart: A Robust Reputation Based Blockchain Scheme in Wireless Sensor Networks

Abstract

The importance given to wireless sensor networks (WSNs) has made them an ideal target for many security issues. Internal attacks are one of the most serious and dangerous threats resulting from the physical capture of the sensor nodes by malicious adversaries. The internal attacker will extract the cryptographic data and reprogram the captured nodes in order to misbehave and to harm the network. Since traditional cryptographic mechanisms are ineffective against this kind of attack it is essential to find additional detection solutions. In order to make distinction between legitimate and fraudulent nodes, trust and reputation mechanisms have been suggested to overcome the limitations of cryptographic methods in securing WSNs. In these mechanisms, reputation values are assigned to neighboring nodes in honest or dishonest manner according to the legitimacy of nodes assigning those values. However, manipulating and modifying reputation values by malicious nodes make these mechanisms vulnerable to many attacks such as: badmouthing, ballo-stufing, on-off, etc. In this paper, we propose a smart reputation mechanism for WSNs (B-Smart) based on blockchain and smart contracts. The purpose of our protocol is to automate the assignment process of reputation values through the use of smarts contracts to prevent falsification of these values by malicious nodes. Saving these contracts in a blockchain will ensure their durability, integrity and effectiveness. The various evaluations conducted demonstrate the robustness of our protocol against a wide range of internal attacks.