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What's with Telegram? Heard mixed opinions on it. (lemmy.world)
submitted 9 months ago by to c/privacy@lemmy.ml
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Some people say it's really privacy-giving and that you should use it as a privacy alternative. Others say it's alao on the big tech side. What's going on with telegram, really?

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[–] 1 point 8 months ago (1 child)

I am not defending Telegram in any way by saying this, but how can you be so certain that content supposely encrypted with MTProto when using Cloud Chat is only stored in plaintext on encrypted disks? Where is the proof of this?

No one can't prove that Telegram use MTProto to encrypt content sent using Cloud Chat, stores them encrypted, and them decrypt them upon opening because the source code for MTProto is closed. So how can you prove that what you're saying is the way they use?

Don't get me wrong in any of this discussion. I don't trust Telegram anymore. I don't trust any closed sourced softwares anymore! But one can't say "it is like this, not like that" without any proof.

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  • [–] 1 point 8 months ago* (last edited 8 months ago)

    Telegram can serve you your old "Cloud" messages, in a decrypted form, on a new device, without any communication with the old device.

    This means that they possess the keys to decrypt the messages, since they can send them to you in a decrypted form.

    Those messages can't even be encrypted with your cloud password (which would be a pretty weak encryption anyways), because you can reset the cloud password via your recovery email, and still retain access to your messages.

    Contrast this with encrypted chats on Matrix, where you have to go through the device verification procedure, which prompts the old device to send decryption keys to the new device (it's actually more complicated but this gets the point across). If you lose access to all your devices (and your recovery key), your encrypted messages are gone, the server admin can't restore them because they simply don't have the key.

    No one can’t prove that Telegram use MTProto to encrypt content sent using Cloud Chat, stores them encrypted, and them decrypt them upon opening because the source code for MTProto is closed. So how can you prove that what you’re saying is the way they use?

    This is a distinction without a difference.

    My claim is:

    They possess the keys to decrypt your messages

    Whether this is implemented via MTProto encryption or disk encryption or whatever, it doesn't matter, they can read your messages if they want to.

    Telegram is actually pretty transparent that Cloud chats are not e2e encrypted in their FAQ. They also go on to babble about "MTProto client-server encryption" but if you spend 2 minutes looking at it, you can see it's just 256-bit AES with a shared key generated via Diffie-Hellman, not too dissimilar from plain HTTPS. In that sense it's about as secure as e-mail over encrypted IMAP/SMTP, or IRC over TLS, or DMs here on lemmy.

    They also claim that their at-rest encryption keys are separate from the data they encrypt, and claim that somehow this "requires court orders from multiple jurisdictions" to force them to give over your data, which is just ridiculous from a legal standpoint and won't stand up in court. And actually, it's way more likely that they will just cave in and give up your message history without a lawsuit at all, just look at what happened to Durov in France.

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