Weilai Yang

Support Vector Machines and Random Forests Modeling for Spam Senders Behavior Analysis

Unwanted and malicious messages dominate email traffic and pose a great threat to the utility of email communications. Reputation systems have been getting momentum as the solution. Such systems extract email senders behavior data based on global sending distribution, analyze them and assign a value of trust to each IP address sending email messages. We build two models for the classification purpose. One is based on support vector machines (SVM) and the other is random forests(RF). Experimental results show that either classifier is effective. RF is slightly more accurate, but more expensive in terms of both time and space. SVM produces similar accuracy in a much faster manner if given modeling parameters. These classifiers can contribute to a reputation system as one source of analysis and increase its accuracy.

VISOR: VoIP Security Using Reputation

Voice over IP (VoIP) is an important step in communications. Along with the benefits of VoIP, such as high efficiency and low cost, come security challenges. Allowing access to the voice communication network over the Internet provides several new opportunities for attackers. This paper summarizes the security challenges and proposes VISOR, a VoIP security architecture. VISOR is a reputation system that monitors VoIP activity, analyzes the global traffic patterns, and distinguishes between wanted and unwanted participants. We describe the components of VISOR and provide an evaluation of its effectiveness.