Trust-Based VoIP Spam Detection Based on Call Duration and Human Relationships

Spam over Internet Telephony (SPIT) will become a serious threat in the near future because of the growing number of Voice over IP (VoIP) users. Due to the real-time processing requirements of voice communication, SPIT is more difficult to filter than email spam. We propose a trust-based mechanism that uses the duration of calls between users to distinguish legitimate callers and spammers. The trust value is adjustable according to the calling behavior. We also propose a trust inference mechanism in order to calculate a trust value for an unknown caller to a callee. Realistic simulation results show that our approaches are effective at discriminating spam calls from legitimate calls.