Forensic Extraction and Analysis of Signal Application in Android Phones

The popularity of smartphones has revolutionised the social media communication and messaging apps such as WhatsApp and Telegram have become the favourite chat apps for smartphone users. The instant messaging service is widely accepted, as it enables the users to easily get connected to the people at the other end. The chat service providers use advanced encryption techniques to ensure safe and secure end to end communication. The increased use of instant messaging apps resulted in rapid growth in the volume of digital evidence for forensic analysis. As there are a lot of privacy issues in WhatsApp and Telegram, people are now moving onto Signal app, which is known to be more privacy preserving and secure than other messaging apps. In this paper, we discuss the forensic acquisition and analysis of Signal messenger app. We propose a new methodology to acquire the Signal app data by the decryption of Signal backup file and recover the chat messages including attachments from Android devices.