A novel blind traffic analysis technique for detection of WhatsApp VoIP calls

摘要

Nowadays social media plays a key role in interpersonal communication. Instant messaging applications, such as WhatsApp, are used by billions of users every day. Such application has recently been upgraded to support voice calls, whose traffic is transported over the top of network operators, as many other Voice over Internet Protocol (VoIP) services. In this work, we have characterized WhatsApp voice calls through blind traffic detection, which allows to differentiate WhatsApp calls from other applications, such as sharing video, photo, or messaging. Traditional techniques for detection of VoIP calls cannot be applied to the WhatsApp case because the traffic is obfuscated. Actually, our proposal only takes into account the WhatsApp traffic stream statistical features, and not the packet content. From the operators' point of view, the benefits of such a tool are manifold: from traffic prioritization to bespoke marketing campaigns to users that heavily produce WhatsApp voice calls.