Internet of Things (IoT) is playing a more and
more important role after its showing up, it covers from
traditional equipment to general household objects such as
WSNs and RFID. With the great potential of IoT, there
come all kinds of challenges. This paper focuses on the
security problems among all other challenges. As IoT is
built on the basis of the Internet, security problems of the
Internet will also show up in IoT. And as IoT contains three
layers: perception layer, transportation layer and application
layer, this paper will analyze the security problems of
each layer separately and try to find new problems and
solutions. This paper also analyzes the cross-layer heterogeneous
integration issues and security issues in detail and
discusses the security issues of IoT as a whole and tries to
find solutions to them. In the end, this paper compares