  Fog or Edge computing has recently attracted broad attention from both
industry and academia. It is deemed as a paradigm shift from the current
centralized cloud computing model and could potentially bring a "Fog-IoT"
architecture that would significantly benefit the future ubiquitous Internet of
Things (IoT) systems and applications. However, it takes a series of key
enabling technologies including emerging technologies to realize such a vision.
In this article, we will survey these key enabling technologies with specific
focuses on security and scalability, which are two very important and
much-needed characteristics for future large-scale deployment. We aim to draw
an overall big picture of the future for the research and development in these
areas.
