See this too. Unfortunately most dissident right people are totally retarded on tech. Telegram is about as safe as using an imageboard that's cloudflared. Maybe less considering every interaction is attributed to an account and a phone number. The hype about security is delusional and used to make telegram seem more than what it is, a social media network that has relatively lax content standards because it's owned by a Russian.
https://blog.cryptographyengineering.com/2024/08/25/telegram-is-not-really-an-encrypted-messaging-app/
>Telegram clearly fails to meet this stronger definition for a simple reason: it does not end-to-end encrypt conversations by default. If you want to use end-to-end encryption in Telegram, you must manually activate an optional end-to-end encryption feature called “Secret Chats” for every single private conversation you want to have. The feature is explicitly not turned on for the vast majority of conversations, and is only available for one-on-one conversations, and never for group chats with more than two people in them.
>Imagine you’re in a “public square” having a large group conversation. In that setting there may be no expectation of strong privacy, and so end-to-end encryption doesn’t really matter to you. But let’s say that you and five friends step out of the square to have a side conversation. Does that conversation deserve strong privacy? It doesn’t really matter what you want, because Telegram won’t provide it, at least not with encryption that protects you from sharing your content with Telegram servers.
>Similarly, imagine you use Telegram for its social media-like features, meaning that you mainly consume content rather than producing it. But one day your friend, who also uses Telegram for similar reasons, notices you’re on the platform and decides she wants to send you a private message. Are you concerned about privacy now? And are you each going to manually turn on the “Secret Chat” feature — even though it requires four explicit clicks through hidden menus, and even though it will prevent you from communicating immediately if one of you is offline?
>According to what I think is the latest encryption spec, Telegram’s Secret Chats feature is based on a custom protocol called MTProto 2.0. This system uses 2048-bit* finite-field Diffie-Hellman key agreement, with group parameters (I think) chosen by the server.* (Since the Diffie-Hellman protocol is only executed interactively, this is why Secret Chats cannot be set up when one user is offline.*) MITM protection is handled by the end-users, who must compare key fingerprints. There are some weird random nonces provided by the server, which I don’t fully understands the purpose of* — and that in the past used to actively make the key exchange totally insecure against a malicious server (but this has long since been fixed.*)
>This data is not typically protected by end-to-end encryption. Even in applications that are broadcast-only, such as Telegram’s channels, there is plenty of useful metadata available about who is listening to a broadcast. That information alone is valuable to people, as evidenced by the enormous amounts of money that traditional broadcasters spend to collect it. Right now all of that information likely exists on Telegram’s servers, where it is available to anyone who wants to collect it.