Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Show HN: ShadowCat – file transfer through QR Codes in a Browser

github.com

Post reply on HN
Print view View original

41–50 of 74 posts

Re: Show HN: ShadowCat – file transfer through QR Codes in a Browser

#44

Post by Levitating »

aliirz wrote: post #32
Levitating wrote: post #31

https://gist.github.com/SMUsamaShah/fd6e275e44009b72f64d0570...

very nice list! Can I suggest adding my https://phntm.sh as well? itis a zero-knowledge file transmission system.

I am not the author, you could leave a comment on the gist instead.

Re: Show HN: ShadowCat – file transfer through QR Codes in a Browser

#45

Post by kig »

This is cool and minimalistic!

I've been noodling on https://qr-send.com which is a slightly more polished version of the "erasure fountain codes + stream of QRs"-idea, inspired by divan's Txqr posts but using Wirehair FEC for the fountain code (basically: you receive ~file size bytes via QR codes and it magically assembles them into the source file regardless of missed codes).

It's an offline-first progressive web app and there are native & wasm builds for the sender. The browser-to-browser transfer falls up to WebRTC when possible because 30 MB/s over wifi beats a 100 kB/s QR stream. The QR scanner is a heavily-optimized WASM build of zbar, scanning at 60 fps on mobile & multiple QRs per frame (but it's finicky! Work in progress.)

Re: Show HN: ShadowCat – file transfer through QR Codes in a Browser

#46

Post by cl3misch »

kig wrote: post #45

This is cool and minimalistic! I've been noodling on https://qr-send.com which is a slightly more polished version of the "erasure fountain codes + stream of QRs"-idea, inspired by divan's Txqr posts but using Wirehair FEC for the fountain code (basically: you receive ~file size bytes via QR codes and it magically assembles them into the source file regardless of missed codes). It's an offline-first progressive web a…

That sounds amazing!

The WebRTC "fallback" basically means the QR code is just a handshake when both devices are on the same network?

Re: Show HN: ShadowCat – file transfer through QR Codes in a Browser

#47

Post by dschep »

kig wrote: post #45

This is cool and minimalistic! I've been noodling on https://qr-send.com which is a slightly more polished version of the "erasure fountain codes + stream of QRs"-idea, inspired by divan's Txqr posts but using Wirehair FEC for the fountain code (basically: you receive ~file size bytes via QR codes and it magically assembles them into the source file regardless of missed codes). It's an offline-first progressive web a…

This looks like a nice polished implementation of the idea, but when I try and use it, I get to "file complete" but then.. nothing? And I see no way to report a problem or bug.

Re: Show HN: ShadowCat – file transfer through QR Codes in a Browser

#48

Post by MattCruikshank »

reaperducer wrote: post #29
MattCruikshank wrote: post #11

I've wanted to use this for an air-gapped communication device. I have a device with a camera and a touch-screen that only uses capacitive charging. I type a message. Bytes are encrypted. I hit send. QR codes flash on my screen. I use my PC or my normal phone to receive the encrypted bytes, and transmit them to you. You have the same device. You have your PC or phone flash encrypted QR codes. You use your device to r…

I have a device with a camera and a touch-screen that only uses capacitive charging. I type a message. Bytes are encrypted. I hit send. QR codes flash on my screen. I use my PC or my normal phone to receive the encrypted bytes, and transmit them to you. You have the same device. You have your PC or phone flash encrypted QR codes. You use your device to receive, and then decrypt. Congratulations. You just invented IrD…

I specifically want this device to have no input or output hardware that could be used without my knowledge. IrDA could absolutely be used without my knowledge.
Post reply on HN