@not2b @Tutanota Haha, end to end does mean what it says, you encrypt, receiver decrypt. But if someone has your keys, they can decrypt as well. And yes facebook has those keys on their servers and they likely have access to those keys. I remember how people were surprised that facebook ads showed stuff they mentioned only on whatsapp. I do use Signal. I wouldn't trust Facebook, or any of big tech company for that matter.
@dieTasse @Tutanota That isn't how end to end encryption works. A key is generated on each device. It is public key encryption. The private key never leaves your device. Signal and WhatsApp use the same technology.