Last month
WhatsApp introduced a "delete for everyone" feature, which allowed users to unsend messages that they'd rather not be read by their intended recipient. There are plenty of reasons to do this - just think of all the embarrassing things you could undo. Whether it's regret or simply a message sent by mistake, it's easy to see why this announcement made users very happy.
This new addition allowed WhatsApp users to be "unsent" within seven minutes, with the catch that the person you sent it to will be able to see that you deleted a message. In fact, there was even a hack that allowed users to get past this threshold and delete regrettable messages from even further back, which you can read more about
here.
Now, the person who unearthed that workaround has discovered something new about the feature. Android Jefe, a Spanish blog about Android phones, discovered a hack that allows users to view the messages that have been deleted - as long as you are an Android user (sorry iOS fans). Santiago S, the author of the blog, wrote:
"We have discovered a way to recover or see messages deleted by the other person in a WhatsApp chat. What we found is that the messages are stored in the notification register of the Android system. So, it's just a matter of entering that record to see the messages that the other person deleted."
Essentially, when a notification comes through to an Android device, it is immediately stored in the notification log, whether or not it has been deleted by the sender. And you can actually access this log, as long as you have the necessary know-how.
The bulk of the data in the log is technical information, but the first 100 characters of the notification message are also recorded. This can be accessed in two ways:
Firstly, you can create a home screen settings widget, in which a 'Notification Registration' option will appear. Or, an alternative solution is to download a notification history app, which displays a list of recent notifications. The first 100 characters of the message will appear in this log, on the line that starts with "android.text."
However, Android Jefe does highlight some important limitations to retrieving messages this way. For one, you can only read the first 100 characters of deleted messages, so the longer messages won't be readable in their full glory. On top of this, the notification log will clear every few hours, or whenever the device is restarted.
This workaround, which it's confirmed works with Android 7 phones, has been tested by some who have found other flaws in his technique. Some have found that the message had to have been read before it was deleted in order for it to appear in the log.
Regardless of the specifics, uncovering this option has made some worry about
WhatsApp's security, as it prides itself on offering end-to-end encryption on its messages. While the message transmission may be safe, this storage may be an issue for those who play things extra safe.
