Decimen Optical Transfer: fountain-coded QR file transfer

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• Hacker News
• Fountain codes are so lit
  by kooi
• I visual reminder that perfect compression is indistinguishable from random noise.
  by thisisauserid
• Naturally the first thing to test should be how far of a link can you create with LOS.

  Radio's get intercepted, this is a cheap laser link.

  by smalltorch
• Apparently if you combine LT with a Reed-Solomon pre-coding stage, then it's a raptor code, which is better because it has a cooler name.
  by inigyou
• Is there a way to negotiate ongoing FPS? I was sending at 60 but only receiving at 40. When I changed TX to 30 the speed went though the roof! I better call a builder.

  Otherwise ridiculously cool project. May author's pillow always be cool on both sides.

  by felooboolooomba
• >Neither mode is encrypted: whatever is on the sending screen is readable by any camera pointed at it.

  Something like this would be good for transferring the public key(s) associated with some cryptographic messaging identity. This would allow that to happen entirely offline. The optical nature of the transfer would prevent a potential MITM. The idea that an identity is being transferred would be fairly easy to impart to the user.

  So the lack of encryption would be a feature and not a bug. This would enable later encryption which could then use any medium for the transfer in a completely secure way.

  by upofadown
• The actual article explaining the use for fountain codes in this use case: https://divan.dev/posts/fountaincodes/
  by legulere
• Neat, finally an easy way of transferring files between devices that doesn't rely on online services -- no clue why we didn't solve that ages ago.

  Adding encryption shouldn't be hard, as long as you can communicate the keys out of band.

  Could probably achieve the same result using audio instead of video, but maybe that would be too annoying?

  by elric