Do auto-deleted messages stay locally?

[qdhj]

Today my close friend told a story, how his friend got in prison (we live in a country with draconian laws, where even harmless and personal things are illegal): she said, police searched through friend's phone and managed to restore the deleted messages in Session, since even after being "deleted after 24h" they were not properly removed from local phone database. She said, that Signal has the same problem, and one should use manual message deleting function to remove them for good.

How close to truth this might be? Does Session really poorly remove (i.e. just visually hide) messages, that are cleared with auto-delete function?

[KeeJef]

Session Desktop, iOS, and Android all use SQLCipher to store message data in an SQLite database. SQLCipher enables SQLite’s secure_delete behavior by default, and we do not change that default in any of the apps. As a result, when a message is manually deleted or removed due to disappearing messages, the message is deleted from the SQLite database and the deleted content is overwritten with zeros (via secure_delete), rather than simply being marked as free space. This should make it quite difficult to recover those messages from the local db.

So I'm not sure what happened in this case, it's hard to know without understanding the exact scenario the device was in, do you know if they were using Session Android or iOS? If so i can move this issue to the relevant repo for further investigation, perhaps the message was recovered from some cloud backup of the device, although both Android and iOS set flags to prevent the db being backed up by default.

[qdhj]

Session Desktop, iOS, and Android all use SQLCipher to store message data in an SQLite database. SQLCipher enables SQLite’s secure_delete behavior by default, and we do not change that default in any of the apps. As a result, when a message is manually deleted or removed due to disappearing messages, the message is deleted from the SQLite database and the deleted content is overwritten with zeros (via secure_delete), rather than simply being marked as free space. This should make it quite difficult to recover those messages from the local db.

So I'm not sure what happened in this case, it's hard to know without understanding the exact scenario the device was in, do you know if they were using Session Android or iOS? If so i can move this issue to the relevant repo for further investigation, perhaps the message was recovered from some cloud backup of the device, although both Android and iOS set flags to prevent the db being backed up by default.

android, honor phone. thanks for the answer, though. i know this might be really anecdotal in practice.