  Sensor networks and Wireless Sensor Networks (WSN) are key components for the
development of the Internet of Things. These networks are subject of two kinds
of constraints. Adaptability by the mean of mutability and evolutivity, and
constrained node resources such as energy consumption, computational complexity
or memory usage. In this context, none of the existing protocols and models
allows reliable peer authentication and trust level management. In the field of
virtual economic transactions, Bitcoin has proposed a new decentralized and
evolutive way to model and acknowledge trust and data validity in a peer
network by the mean of the blockchain. We propose a new security model and its
protocol based on the blockchain technology to ensure validity and integrity of
cryptographic authentication data and associate peer trust level, from the
beginning to the end of the sensor network lifetime.
