Information diffusion and social influence
Security and privacy
Security: One of the key security threats plaguing social systems is abuse of services. Service abuse takes many forms -- e.g., users are flooded with spam messages for the purpose of promoting businesses or for spreading malware, and crowd-sourced content rating services are tampered by fake or Sybil accounts to manipulate ratings. Such attacks severely degrade the quality of service provided by such social networking websites. Our work tries to understand existing attacks and defenses, and propose novel techniques to build robust and practical systems to limit service abuse.
Privacy: Users today are uploading large amounts of content that are personal in nature. Such sensitive pieces of content are shared with the OSN provider, third party applications, and other users of the services. This has led to serious privacy leakage issues and also increased the privacy management overhead for the user. We perform large-scale measurement studies to understand privacy risks with sharing personal content online and propose new systems to provide strong privacy guarantees.
Limiting service abuse by Sybil identities
- Understanding spammer infiltration in social networks and defending against collusion attacks
- Understanding privacy leakage via the social network
- Understanding the user privacy management overhead
- Limiting privacy leakage via third party apps
- Towards decentralized OSNs for better control over personal data
- Simplifying Access Control specification in OSNs
- Towards better user privacy via exposure control