Private Twitter messages should use end-to-end encryption, in such a way that no one can spy on them: to support it, of course on Twitter, is the new owner of the Elon Musk platform, who uses Signal, one of the reference points for secure communication, as a yardstick. It is worth remembering that even WhatsApp has always used end-to-end encryption; there is also on Telegram, however it is not active by default, it does not work for group chats and uses a proprietary algorithm that according to some security experts is less reliable than others.
Very simplifying, end-to-end encryption works in such a way that only the extremes of a conversation (senders and recipients, in practice) they have the keys to decrypt a message. The intermediate “stages”, such as the servers that are responsible for transmitting the message, receive and send only encrypted information, which cannot be decrypted. It follows that those with access to the servers cannot know the content of the conversations – and therefore it is not a channel that can be exploited by hackers or government agencies. This does not mean that an end-to-end encrypted chat is absolutely impenetrable, but it certainly is a significant “plus” for your privacy.
End-to-end encryption is therefore very desirable, but involves several challenges and complications to be implemented correctly – and user-side compromises. One of the main ones, which WhatsApp is only now learning to circumvent, is the exploitation of the same account on multiple devices. It is precisely because of the choice not to compromise on security that we have used a WhatsApp Web for years subject to the online availability of the main smartphone. Twitter would have to make some pretty major changes to its backend to ensure a true multi-device. Or, as seen in other platforms, it could implement a “partial” E2E in which the encrypted conversation is only available on the devices where it was initiated.
In the days immediately following the announcement of the acquisition, the founder of Tesla and SpaceX (among many others) has repeatedly expressed his intention to make the platform a herald of free speech, at least within the limits of legality. Musk even went so far as to say that Truth, the social network created by Donald Trump, exists only because Twitter has not been able to guarantee it. But it is the first time that we talk more explicitly about the privacy of users, even if if we want it can be argued that it falls, with certain limits and precautions, in the same sphere of interest.