  Smart devices are considered as an integral part of Internet of Things (IoT),
have an aim to make a dynamic network to exchange information, collect data,
analysis, and make optimal decisions in an autonomous way to achieve more
efficient, automatic, and economical services. Message dissemination among
these smart devices allows adding new features, sending updated instructions,
alerts or safety messages, informing the pricing information or billing amount,
incentives, and installing security patches. On one hand, such message
disseminations are directly beneficial to the all parties involved in the IoT
system. On the other hand, due to remote procedure, smart devices, vendors, and
other involved authorities might have to meet a number of security, privacy,
and performance related concerns while disseminating messages among targeted
devices. To this end, in this paper, we design STarEdgeChain, a security and
privacy aware targeted message dissemination in IoT to show how blockchain
along with advanced cryptographic techniques are devoted to address such
concerns. In fact, the STarEdgeChain employs a permissioned blockchain assisted
edge computing in order to expedite a single signcrypted message dissemination
among targeted groups of devices, at the same time avoiding the dependency of
utilizing multiple unicasting approaches. Finally, we develop a software
prototype of STarEdgeChain and show it's practicability for smart devices. The
codes are publicly available at https://github.com/mbaqer/Blockchain-IoT
