Abstract:
Smart meters operate based on their firmware
ruling the hardware. The firmware occasionally needs to be
updated to fix bugs and improve the services. Since the smart
meter firmware is proprietary, the update file should be communicated
to the smart meters in a secure way. In addition, the
firmware update may target a specific subgroup of the smart
meters rather than all of them in which case access control is
required. In this paper, we address the problem of updating
the smart meter firmware securely in an IEEE 802.11s-based
AMI network and develop a secure and reliable multicast-overbroadcast
protocol by making use of ciphertext-policy attributebased
signcryption (CP-ABSC) to provide not only confidentiality
and access control but also message authentication. CP-ABSC
is employed to signcrypt both the firmware update file and
the firmware update request based on an access tree such that
the signcrypted update file and request can be designcrypted
by the smart meters possessing the attributes that can satisfy
the access tree. The preliminary tests showed that increased
size of the request due to signcryption reduces reliability of the
protocol. Therefore, we employ random linear network coding
along with CP-ABSC in order to increase the reliability and use
the bandwidth and processing resources efficiently. We assessed
the performance of the proposed protocol under ns-3 network
simulator. The simulation results have shown that the protocol
can accomplish the process of downloading a firmware update
without needing any human intervention while consuming less
bandwidth when compared to a baseline that employs unicasting.
