FlyTrap: A Blockchain-based Proxy for Authorisation and Audit of MQTT Connections

MQTT brokers have become integral components of many IoT systems. However, the authorisation mechanisms defined by the MQTT protocol remain optional which may result in weak security configurations of MQTT brokers. In addition, with increasing prevalence of IoT solutions across many domains, MQTT brokers are used to forward various types of data including material that may be personal or commercially sensitive. Such data may be subject to a number of regulations (e.g. GDPR) which require trusted and auditable reporting that goes beyond local log files maintained by brokers. In this paper, we explore the potential of blockchains to facilitate a trusted and secure support infrastructure for authorisation and audit of MQTT connections.