An attribute-based reliable multicast-over-broadcast protocol for firmware updates in smart meter networks

The Smart Grid (SG) initiative introduces a two-way communication between utility companies and the consumers thanks to Advanced Metering Infrastructure (AMI) networks. One of the most crucial components that constitute an AMI network is smart meters (SMs). SMs execute some programs called firmware to rule the hardware. The firmware occasionally needs to be updated to fix bugs and improve the services. Since the SM firmware is proprietary, the update file should be communicated to the SMs in a secure way. In addition, the firmware update can target a specific subgroup of the SMs rather than all of them. In this paper, we address the problem of multicasting the firmware update securely in an IEEE 802.11s-based SG AMI network and develop a secure and reliable multicast-over-broadcast protocol by making use of ciphertext-policy attribute-based signcryption (CP-ABSC) to provide not only confidentiality and access control but also message authentication. A hash of the firmware update is signcrypted based on an access tree such that the hash can be designcrypted only by the SMs possessing the attributes that can satisfy the access tree. In this paper, we propose an attribute-based multicast-over-broadcast protocol called Broadcast-Alarm (Bcast-Alarm) which is both secure and reliable. We assessed its performance under ns-3 network simulator. The simulation results have shown that Bcast-Alarm protocol can complete downloading a firmware update file by consuming comparable amount of bandwidth compared to unicasting.