Online social networks serve as a promising platform for social eliteness and financial gain. With such a promise or dream, zombie accounts, behind which stand no real users, become prevalent. The detection of such accounts has been games of cat and mouse, with more and more sophisticated methods used by zombie account managers. In this work, we propose a new zombie account detection technique ...

We set out to understand the effects of differing language on the ability of cybercriminals to navigate webmail accounts and locate sensitive information in them. To this end, we configured thirty Gmail honeypot accounts with English, Romanian, and Greek language settings. We populated the accounts with email messages in those languages by subscribing them to selected online newsletters. We hid...

We describe two techniques for reducing the effectiveness of sybil attacks, in which an attacker uses a large number of fake user accounts to increase his reputation. The first technique uses a novel transformation of the ranks returned by the PageRank system. This transformation not only reduces susceptibility to sybil attacks but also provides an intuitive and easily interpreted reputation sc...

Managing trust in cloud environments is emerging as an important issue in recent years. The highly dynamic, distributed, and non-transparent nature of cloud services makes the trust management of these services difficult. Malicious users may collude to give multiple misleading trust feedback to disadvantage a cloud service, or create several accounts and then leave misleading trust feedback to ...

We use techniques from evolutionary game theory to analyze the conditions under which guilt can provide individual fitness benefits, and so evolve. In particular, we focus on the benefits of guilty apology. We consider models where actors err in an iterated prisoner’s dilemma and have the option to apologize. Guilt either improves the trustworthiness of apology or imposes a cost on actors who a...

Online reviews play a crucial role in helping consumers evaluate and compare products and services. However, review hosting sites are often targeted by opinion spamming. In recent years, many such sites have put a great deal of effort in building effective review filtering systems to detect fake reviews and to block malicious accounts. Thus, fraudsters or spammers now turn to compromise, purcha...