A Study on Video-Files Sent Through Popular Instant Messaging Applications on Smartphones for Forensics Investigation

Abstract

With the advent of smartphones and cheaper internet services, internet-based communication via instant messaging applications has become very widespread in today’s world. As a result, cybercrime has risen as well. Thus, forensic investigators should understand how data files are altered when they are transferred via these popular instant messaging apps through smartphones. In the present paper, our aim is to focus on the study of variation in the properties of sample short video message when exchanged through popular instant messaging applications i.e. WhatsApp, Facebook Messenger, QQi and Telegram. Any video recorded on a smartphone has various parameters linked to its audio and video properties. This paper presents a methodology of extraction and analysis of these video files using freewares available online. It was found that every instant messaging application has its unique compression format which affects the properties of any data file accordingly. Comparison of the parameters of received video file obtained from this study shows that when such files get transmitted through Facebook Messenger and Telegram, it faced maximum degradation in both audio and video parameters. But when transferred through QQi and WhatsApp application, audio and video parameters of file has not got affected for used sample short video of ~18 sec. Furthermore, with QQi, we have observed that even the Hash value of file has also not got changed. Utilizing the results presented in this paper, forensic investigators can study the authenticity of such instant messages in cases involving legal matters by considering facts about data compression.