Many often you need to delete your WhatsApp chat conversations, but when you delete them, are they actually deleted? According to this Verge report, the chat conversations that you delete in WhatsApp might not be completely deleted and their traces can be detected by someone who wants to detect them. As it happens with digital information, whenever it is deleted, it isn’t actually physically removed from your disk, it’s just that the space occupied by that digital information is free to be overwritten. Unless that space is overwritten, the information is there.
The link above says that an iOS researcher Jonathan Zdziarski discovered that WhatsApp retains and stores a forensic trace of the chat logs even after the chats have been deleted. So someone who knows how to access your device physically, he or she can easily retrieve your deleted WhatsApp chats. The WhatsApp chat conversations that you are regularly deleting, are not completely deleted. Although the data is marked as deleted, since it hasn’t been overwritten, it can be recovered using forensic tools. The problem might not be WhatsApp related: WhatsApp uses SQLite which doesn’t completely delete the information marked for deleting – it simply makes the space available for other information to be written in case no space is available.
What about encryption? Doesn’t WhatsApp encrypt your messages? The messages are encrypted when they leave your device. As long as the information is on your device, it is easily accessible to someone who wants to access it. While the chat conversations are travelling in the Internet, they are encrypted but as soon as they reach your phone they are decrypted using a unique key.
Also many cloud backup services routinely back up your WhatsApp messages and when they are backed up, they are backed up in a non-encrypted format. For example, in iPhones, your WhatsApp chat conversations are routinely backed up in iCloud. So if someone can access your iCloud account, he or she can also access your WhatsApp conversations. The similar problem also exists on Android phone where you are prompted to backup your WhatsApp chat conversations in Google Drive. If some law enforcement agency wants to get hold of your conversations, it’s as simple as getting hold of your device physically or logging into your cloud backup service because when you delete WhatsApp chat conversations they are not completely related until something else overwrites them.