  Emerging in recent years, open edge computing platforms (OECPs) claim
large-scale edge nodes, the extensive usage and adoption, as well as the
openness to any third parties to join as edge nodes. For instance,
OneThingCloud, a major OECP operated in China, advertises 5 million edge nodes,
70TB bandwidth, and 1,500PB storage. However, little information is publicly
available for such OECPs with regards to their technical mechanisms and
involvement in edge computing activities. Furthermore, different from known
edge computing paradigms, OECPs feature an open ecosystem wherein any third
party can participate as edge nodes and earn revenue for the contribution of
computing and bandwidth resources, which, however, can introduce byzantine or
even malicious edge nodes and thus break the traditional threat model for edge
computing. In this study, we conduct the first empirical study on two
representative OECPs, which is made possible through the deployment of edge
nodes across locations, the efficient and semi-automatic analysis of edge
traffic as well as the carefully designed security experiments. As the results,
a set of novel findings and insights have been distilled with regards to their
technical mechanisms, the landscape of edge nodes, the usage and adoption, and
the practical security/privacy risks. Particularly, millions of daily active
edge nodes have been observed, which feature a wide distribution in the network
space and the extensive adoption in content delivery towards end users of 16
popular Internet services. Also, multiple practical and concerning security
risks have been identified along with acknowledgements received from relevant
parties, e.g., the exposure of long-term and cross-edge-node credentials, the
co-location with malicious activities of diverse categories, the failures of
TLS certificate verification, the extensive information leakage against end
users, etc.
