Research

Online Social Networks and Cyber Security

Twitter botnets and spam attacks

Dr. Shi Zhou’s team discovered two of the largest botnets on Twitter: (1) the Star Wars Botnet with >360,000 bots and (2) the Bursty Botnet with >500,000  bots.  Recently they uncovered a large-scale spam attack launched by the Bursty Botnet and tracked down the botmaster of the botnet and the attack — perhaps  the first time in this field of research.

They are also working on advanced methods to detect fraud users and publishers on online advertisement bidding platform.

Critical hybrid epidemic spreading

Dr. Zhou’s team introduced the theory of critical hybrid epidemics, where used a meta-population model to explain how to combine simple, ineffective spreading mechanisms to produce extremely infectious and persistent epidemics. This theory explained the massive outbreak of Internet worm Conficker and led to the first mathematical model that reproduces the full course of HIV infection in human body. Dr. Zhou also studies hybrid information diffusion in society and cyberspace, and new strategies to assist/control hybrid spreading.

Here is a collection of media reports on our research on Twitter bots and hybrid epidemics.

Network Science and Complex Networks

Rich-club phenomenon

Dr. Zhou’s team reported the rich-club pheromone in the Internet topology. Today, the rich-club coefficient has been widely used as a key metrics to quantify the structure of networks across a wide range of domains, including transport, social and biological systems.

Positive-feedback preference (PFP) model

Dr. Zhou’s team proposed the Positive-Feedback Preference model, which is one of the most advanced Internet topology generator to date. The model provides insights into the evolution of the Internet topology, and it has been widely used in Internet research.

Structural constraints in networks

Dr. Zhou’s team introduced novel link rewiring algorithms to explore the structural constraints in complex networks. They revealed that a network’s degree distribution has little constraint on the network’s rich-club structure.

Second-order assortative mixing in social networks

Dr. Zhou’s team reported that many social networks exhibit the second-order assortative mixing, often significantly stronger than the first-order assortative mixing. This property is absent in technological or biological networks.

Bitmap of sorted adjacent matrix (BOSAM)

Dr. Zhou’s team introduced a novel network visualisation technique, called the bitmap of sorted adjacent matrix (BOSAM). It is an effective tool to compare between networks.

Internet Routing and Cloud Computing

Inference of Internet AS relationships

Dr. Zhou’s team introduced a novel approach to infer the Type of Relationships (ToR) between the Autonomous Systems (AS) on the Internet based on the BGP Community attribute, including multilateral peering at IXPs. They produced so far the most accurate and reliable AS relationship data. They are also working on models to predict the exact routing paths between any two IP addresses across the Internet.

Universal cloud classification (UCC)

Dr. Zhou’s team proposed the Universal Cloud Classification as a universal scheme to uniquely identify each cloud provider, service and tenant across the global Internet. UCC IDs can be embedded in IP packet headers for traffic classification, which can support a variety of routing, QoS and security applications. Cisco has filed a series of patents based on the concept of UCC.