When you press ‘delete’ on your iPhone, the general expectation is that you have actually deleted that item. It’s gone. Destroyed.
In his blog “WhatsApp Forensic Artifacts: Chats Aren’t Being Deleted”, Jonathan Zdziarski explains how WhatsApp still leaves a forensic trace of every message you’ve sent hidden on the phone, even if you’ve deleted them.
“Simply preserving deleted data on a secure device is not usually a significant issue,” explains Zdziarski. “But when that data comes off the device as freely as WhatsApp’s database does, it poses a rather serious risk to privacy.”
According to Zdziarski, even when a chat is deleted on the iPhone a tiny record of the full chat remains. It seems the only way to completely remove the record is to delete the app entirely.
Why is this a problem? “Law enforcement can potentially issue a warrant with Apple to obtain your deleted WhatsApp chat logs, which may include deleted messages.” explains Zdziarski.
While for the general user this might not be the end of the world, Zdziarski does point out that for some, this will be a concerning revelation.
”The design choices they make when developing a secure messaging app has critical implications for journalists, political dissenters, those in countries that don’t respect free speech, and many others.”
“A poor design choice could quite realistically result in innocent people – sometimes people crucial to liberty – being imprisoned.”
While this is concerning, WhatsApp has made significant strides towards protecting its users by introducing end-to-end encryption on all its forms of communication.
Of course for a use who needs that encryption, now knowing that the chat will still be freely available to a hacker on the physical device could be worrying.
According to Zdziarski this is not a problem that’s limited just to WhatsApp but affects Apple’s entire operating system.
Calling iOS a “forensics gold mine” the researcher believes that in modern technology as a whole there are simply too many gaps in security.
“To Apple’s credit, they’ve done a stellar job of improving the security of iOS devices in general (e.g. the “front door”), but we know that they, just like every other manufacturer, is still dancing on the lip of the volcano.”