387
blastQR: send files completely offline over QR codes. Up to 1.4 MB/s (lemmy.dbzer0.com)
submitted 1 day ago by to c/privacy@lemmy.ml
103 comments fedilink hide all child comments
 

https://codeberg.org/blast/blastqr

Hello! I've been working on blastQR for a couple of years now and I thought this community might find it useful. Feel free to try it and ask me anything!

blastQR is a fully open-source file transfer app and protocol that works completely offline. You can even use it in airplane mode. Data is transferred through sequences of QR codes displayed on a sender device and scanned by a receiver device's camera. It uses RaptorQ codes so the receiver can recover the file from any sufficiently large subset of frames.

Note that although I have made use of AI as a coding assistant I do not consider this to be a vibe-coded app and I do plan to continue improving it and supporting it in the future.

See video of blastQR in action: https://github.com/user-attachments/assets/038a2567-70c8-47c8-b165-dea858d1aef3

Here are some of the key features:

  • Works fully offline: No internet, Wi-Fi, Bluetooth or servers. Your data stays offline.
  • One-to-many distribution: Share the same file with multiple devices simultaneously using a single blastQR broadcast.
  • Cross-platform: Android, iOS, macOS, Linux and Windows, plus a command-line tool that can send from a terminal, even over SSH.
  • Password encryption: You can optionally encrypt files with an auto-generated password or a custom one.
  • Media compression: The app supports lossy image compression and video transcoding for quicker transfers.
  • Multiple codes on screen: Shows multiple QR codes at once for higher speed. With 8 codes at 60 fps, transfers peak at around 1.4 MB/s.
  • Send multiple files in one go: They're zipped into one transfer and unpacked into separate files on the receiver.
  • Sound feedback: The receiver plays a short tone when it has the whole file, and the sender stops automatically when it hears it.
  • Start scanning at any point: No need to catch every code, just keep the camera on the screen until it's done. Blurry or missed codes don't matter.
  • Regular QR scanner: You can also scan normal QR codes and save them.
  • Open protocol that other apps can implement
  • Built-in file manager

I'm trying to build a small community around the project so it can be improved and maintained and so it can reach more people in the future.

Downloads for all platforms can be found here: https://codeberg.org/blast/blastqr/releases/latest

you are viewing a single comment's thread
view the rest of the comments
[–] 10 points 17 hours ago (2 children)

If you're in an environment where turning on your cell radios could compromise you then you'd like something that operates through something other than radio. Two people sharing data at a protest for example.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 2 child comments
    •
  • [–] 2 points 15 hours ago (1 child)

    LocalSend uses wifi rather than cell but you’re right that a protest could be a good place not to turn on any radios. It’s also a good place not to bring a phone at all, even if you’ve thought in advance to install a visual data transfer program like this. But you have a good point.

  • permalink
  • fedilink
  • source
  • parent
  • hideshow 1 child comment
    •
  • [–] 4 points 14 hours ago

    There's a wide range of threat levels someone could be managing at a protest. Lots of people don't feel particularly at risk from being grabbed and having their phone cracked, but still don't want to be added into a database of people opposed to a regime because an automated mass surveillance system sniffed their radio signature. If you're not expecting a personal assault phones can be useful for documenting police, promoting the event afterward, and accessing emergency services.

    I don't think the "don't bring a phone to a protest" advice is good unless you think it's likely you could be in a position to lose control of it. The tradeoffs for that level of safety don't make it worth doing for random citizen protesters. I do think concealing your face and turning off your radios is a good idea, because those are very realistic threat vectors for a generic citizen protester. Of course you could have the best of both worlds by getting a burner phone, but I don't think many people are that prepared.

  • permalink
  • fedilink
  • source
  • parent