By analysing signalling messages exchanged during a WhatsApp call using an Android device, the researchers were able to closely examine the authentication process of WhatsApp clients; discover what codec WhatsApp is using for voice media streams (Opus at 8 or 16 kHz sampling rates); understand how relay servers are announced and the relay election mechanism; and understand how clients announce their endpoint addresses for media streams.
A paper about the study, entitled WhatsApp Network Forensics: Decrypting and Understanding WhatsApp Call Signaling Messages, was published in the scholarly journal Digital Investigation. The article was co-authored by F. Karpisek of Brno University of Technology in the Czech Republic, and Ibrahim Baggili and Frank Breitinger, co-directors of the Cyber Forensics Research & Education Group at the University of New Haven.
via John van Gils.
#whatsapp #android #research #opus #reverse_engineering #forensic