An implementation of a High Assurance Smart Meter using Protected Module Architectures

摘要

Due to ongoing changes in the power grid towards decentralised andhighly volatile energy production, smart electricity meters are required to providefine-grained measurementand timely remote access to consumption andproduction data. This enables flexible tariffing and dynamic loadoptimisation. As the power grid forms part of the critical infrastructureof our society, increasing the resilience of the grid's software componentsagainst failures and attacks is vitally important.In this paper we explore the use of Protected Module Architectures (PMAs)to securely implement and deploy software for smart electricity meters.Outlining security challenges and an architectural solution in the light ofsecurity features provided by PMAs, we evaluate a proof-of-conceptimplementation of a security-focused smart metering scenario. Ourimplementation is based on Sancus, an embedded PMA for low-powermicrocontrollers. The evaluation of our prototype provides strongindication for the feasibility of implementing a PMA-based high assurancesmart meter with a very small software Trusted Computing Base, which wouldbe suitable for security certification and formal verification.