Facebook-owned WhatsApp recently increased the time limit to delete messages for everyone to 4,096 seconds (or 68 minutes and 16 seconds). The messaging platform increased the limit from 420 seconds (or seven minutes) as part of WhatsApp beta for Android version 2.18.69.
The extension of time limit was also made available later on iOS and Windows Phone updates. However, some users have already taken advantage of the ‘Delete for Everyone’ feature via modded versions of the app to delete messages dating back to three years. WhatsApp users can understand that a message has been deleted with the “This message has been deleted” prompt in their chat window. Those using modded or unauthorized versions of the app have tricked this notification system to delete old messages.
Now, WhatsApp has silently added another feature called ‘Block revoke request’ in order to stop users from exploiting the ‘Delete for Everyone’ feature. As observed by WABetaInfo, the feature works by sending a message to the recipient whenever the sender tries to delete a message for everyone. This message has the same ID as the one the user wants to delete.
WhatsApp then finds a message in the database having the same ID and matches it with that of the message requested to be revoked by the sender. It then checks the date related information of the message saved in the database. The algorithm has been programmed to perform the delete operation only if the current date is less than 24 hours of the date of the saved message. This will ensure that nobody can fool the system to delete messages for everyone dating back to three years.
With this new addition, WhatsApp is sticking to 24 hours as a reference time period in order to ensure that the recipient or recipients in case of group chat have ample time to receive the revoke request. The update is a step to curb exploitation of a feature that was deemed useful by those using the platform.