We all know Signal, Matrix, Telegram, SimpleX, etc… But if you can’t access the internet you can’t communicate. Pretty logic. But would it be possible, at least theoretically, to create an app that permits to message people even if the internet goes down?

It might be a dumb question I really have no idea to be honest.

  • Mr. Zeus@feddit.org
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    3 days ago

    wouldn’t a cheap walkie-talkie be more practical in that situation?

    That’s not secure or encrypted

    • ERROR: Earth.exe has crashed@lemmy.dbzer0.com
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      3 days ago

      You can encrypt a radio.

      Rattlegram is an app on iOS/Android that alllows converting text to audio and play it over your phone’s speaker

      Secure Space Encryptor (SSE) (known as Paranoia Text Encryption on iOS) is an Open Source app that can encrypt text.

      1. Use SSE to encrypt text
      2. Copy-Paste the Ciphertext to Rattlegram
      3. Sent it over the radio
      4. On the other end, use Raddlegram to turn the audio back to the ciphertext
      5. Use SSE to decrypt.

      Voila! Off-Grid Encrypted communications.

      Warning: Encryption over radio is illegal in many countries 😉 (but fuck the law lol, who cares)

      • Mr. Zeus@feddit.org
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        2 days ago

        You can encrypt a radio.

        Yes, but that requires you and the one(s) you’re communicating with to mod some radios and then to keep those radios secret, which won’t be easy once you start using them, especially in a situation like that where the government would probably be scanning those frequencies for exactly that

        • ERROR: Earth.exe has crashed@lemmy.dbzer0.com
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          2 days ago

          Don’t need to modify them. Use my method above

          Just have extra phones you don’t connect to the internet with and install the apps via loading .apk files. You can even use old phones in a dusty shelf somewhere.

          Do not transmit from your house, travel to somewhere without cameras transmit your messages, then leave. Avoid using motor vehicles, ride a bike. There are ham radios that are small enough to fit in your pocket. You can get a longer antenna to transmit further.

          When you return, wipe the phones. You should have the .apk files stored in an microsd card and create a encrypted volume with a hidden partition, put tax documents in the normal partition, put the .apk files in the hidden partition. Label this volume “Tax [Year]-[Year]” Hide the microsd card somewhere, bur avoid putting it like under a floor board, that’d be too suspicious. Put them in your underwhere or something like that. Its not unusual to encrypt tax documents or hide them. You have plaudible deniability. And your radios are all just normal radios. (Don’t save the frequencies in your radio lol)

          You should probably also get a Ham radio license as a cover, preferrably you should already have a ham radio license years in advance, before you start to do encrypted transmissions. Get a bunch of radios and have them on display in your home. Don’t hide the fact that you have radios Hiding in plainsight is the best way to hide. Make normal, unencrypted communications frequently, just have normal chats with people. (This is assuming your country don’t just ban radios outright)

          You have to schedule the transmission/receiving times in advance, so your contacts can prepare for it. Choose a random frequency that no one else is using.

          Then once a while, you travel to a random location, the further away from your house, the better. You send short bursts of encrypted transmisions. Keep transmissions under 2 minutes.

          If they search your home, all they see is a radio enthusiast with a bunch of regular non-modified radios and some old phones in the drawers.

          This is best if there are a lot of ham radio people around your area.

          There are so many radio enthusiasts. In the US, there are more than 750,000 people with a license in Ham radios, they can’t arrest everyone. (Again, this is assuming they don’t just ban radios outright)

          You could chance your frequency to those used by walkie talkies. That is a lower range, but also broadens the possible perpetrators, since walkie talkies are everywhere, they are in many stores like walmarts, bestbuys, targets… etc…