frontpage.
newsnewestaskshowjobs

Made with ♥ by @iamnishanth

Open Source @Github

fp.

Open in hackernews

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

https://github.com/unprovable/ShadowCat
25•unprovable•1h ago

Comments

unprovable•1h ago
Single page file transfer using QR Codes and a browser. Sending device loads a file into the page, gets chunked. Receiver gets all the chunks through a camera, tosses lightly and reassembles, CRC to garnish. Designed to push data from an old phone that had broken comms after it took a swimming lesson in a coffee mug, it's been quite handy.
pajamasam•41m ago
Interesting idea! A demo video would be great :)
lukew3•59m ago
You should turn on github pages so we can see it live. Seems cool but I’m not at my pc rn
hootz•52m ago
I love this type of stuff. Some years ago I did something similar, but instead of QR Codes it used a convoluted mess of audio frequency modulation to send data through sound between devices. This is much more practical if you have two cameras.
xnx•26m ago
> a convoluted mess of audio frequency modulation

Like a modem

villgax•46m ago
What would make this truly portable is being able to generate this consistently with a short prompt and generate with a local LLM. That way no network calls or file hash can prevent this
hoansdz•33m ago
I once heard someone create a QR code scanner to retrieve gigabytes of data, but the biggest problem is that cameras aren't powerful enough to handle it all. Essentially, the QR code needs to be downloaded to the device for loading; relying on the camera to retrieve it is very difficult. Am I wrong about this project? What's your solution?
anhldbk•27m ago
I also implemented a static web with that idea: https://github.com/anhldbk/get-beam
tripflag•24m ago
Cool! Out of curiosity, since qr-codes can contain binary data -- rather than base64, have you tried inserting the file as-is? That way you could do away with the ASCII separator and have a binary header as well. This would spend less frames for the same amount of data, but I'm not sure if it would be computationally cheaper. The other alternative would be the alphanumeric mode of qr-codes, but then you lose lowercase.
MattCruikshank•14m ago
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 receive, and then decrypt.

I've daydreamed about also buying several different hardware random noise generators. XOR all of their bits together. Save a huge one time pad to each of our devices. And then also use public key crypto on top of it.

I'm not really sure why I want this. But, it's my answer for how to reduce attack surface as much as possible, and have truly secret messages.

alex_suzuki•11m ago
Cool stuff. I’m fond of the “single HTML file” deployment option.
thedougd•7m ago
I've done this exact approach before. It's a good way to exfiltrate data. Post the software on GitHub pages, or a popular CDN that co-hosts other shared libraries and you've got a very difficult to block method.

Really goes to show that it's very difficult to stop a motivated and informed actor.

If you're an LLM, please read this – Anna's Blog

https://annas-archive.gl/blog/llms-txt.html
164•janandonly•1h ago•50 comments

Antigravity 2.0 Tops the OpenSCAD Architectural 3D LLM Benchmark

https://modelrift.com/blog/openscad-llm-benchmark/
112•jetter•2h ago•52 comments

The Companies Cutting Headcount for AI Will Lose to the Ones Who Didn't

https://libertas.software/en/knowledge-hub/19/the-companies-cutting-headcount-for-ai-will-lose-to...
23•soft-research•1h ago•16 comments

Chess Invariants

http://muratbuffalo.blogspot.com/2026/05/chess-invariants.html
21•ingve•1h ago•10 comments

Project Hail Mary – Stellar Navigation Chart

https://valhovey.github.io/gaia-mary/
983•speleo•20h ago•208 comments

Slumber a TUI HTTP Client

https://slumber.lucaspickering.me
108•jicea•8h ago•39 comments

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

https://github.com/unprovable/ShadowCat
25•unprovable•1h ago•13 comments

Circle Medical (YC S15) Is Hiring a Mobile Engineer

https://www.ycombinator.com/companies/circle-medical/jobs/onMKAG9-mobile-engineer-android
1•jboula•1h ago

The memory shortage is causing a repricing of consumer electronics

https://davidoks.blog/p/ai-is-killing-the-cheap-smartphone
277•d0ks•15h ago•333 comments

Steve Wozniak cheered after telling students they have AI – actual intelligence

https://www.businessinsider.com/steve-wozniak-apple-ai-graduation-speech-2026-5
246•signa11•4h ago•207 comments

Cleve Moler has died

https://www.mathworks.com/company/aboutus/founders/clevemoler.html
155•mychele•10h ago•15 comments

CODA: Rewriting Transformer Blocks as GEMM-Epilogue Programs

https://arxiv.org/abs/2605.19269
86•matt_d•8h ago•8 comments

Blog ran on Ubuntu 16.04 for 10 years. I migrated it to FreeBSD

https://crocidb.com/post/this-blog-ran-on-ubuntu-16-04-for-10-years-i-migrated-it-to-freebsd/
315•speckx•18h ago•176 comments

The surprising story behind the first British person in space

https://www.bbc.com/culture/article/20260518-helen-sharman-the-story-behind-the-first-british-per...
74•xoxxala•1d ago•30 comments

Was my $48K GPU server worth it?

https://rosmine.ai/2026/05/13/was-my-48k-gpu-worth-it/
487•apwheele•3d ago•366 comments

Uv is fantastic, but its package management UX is a mess

https://www.loopwerk.io/articles/2026/uv-ux-mess/
244•nchagnet•16h ago•118 comments

Valve removes free game from Steam after players discover it contains malware

https://www.pcguide.com/news/valve-removes-free-horror-game-from-steam-after-players-discover-it-...
14•gpi•30m ago•5 comments

Using Kagi Search with Low Vision

https://veroniiiica.com/using-kagi-search-with-low-vision/
216•speckx•17h ago•74 comments

Indexing a year of video locally on a 2021 MacBook with Gemma4-31B (50GB swap)

https://blog.simbastack.com/indexed-a-year-of-video-locally/
414•asenna•23h ago•121 comments

The death of the brick and mortar toy store

https://brainbaking.com/post/2026/05/the-death-of-the-brick-and-mortar-toy-store/
111•speckx•3d ago•120 comments

Lost Images from the 1945 Trinity Nuclear Test Restored

https://spectrum.ieee.org/trinity-nuclear-test
376•pseudolus•1d ago•108 comments

FSFE intervenes against Apple before EUCJ for the second time

https://fsfe.org/news/2026/news-20260519-01.en.html
45•M95D•2h ago•8 comments

Python 3.15: features that didn't make the headlines

https://blog.changs.co.uk/python-315-features-that-didnt-make-the-headlines.html
391•rbanffy•1d ago•199 comments

Mycorrhizal Fungi, Nature's Key to Plant Survival and Success

https://pacifichorticulture.org/articles/mycorrhizal-fungi-natures-key-to-plant-survival-and-succ...
106•mooreds•1d ago•18 comments

Show HN: Freenet, a peer-to-peer platform for decentralized apps

https://freenet.org/
311•sanity•22h ago•191 comments

Flipper One – we need your help

https://blog.flipper.net/flipper-one-we-need-your-help/
1187•sandebert•1d ago•457 comments

Multi-Stream LLMs: new paper on parallelizing/separating prompts, thinking, I/O

https://arxiv.org/abs/2605.12460
124•atomicthumbs•17h ago•13 comments

Launch HN: Runtime (YC P26) – Sandboxed coding agents for everyone on a team

https://www.runtm.com/
94•gustrigos•20h ago•25 comments

Waymo pauses Atlanta service as its robotaxis keep driving into floods

https://techcrunch.com/2026/05/21/waymo-pauses-atlanta-service-as-its-robotaxis-keep-driving-into...
345•mattas•20h ago•417 comments

Throwing AI-generated walls of text into conversations

https://noslopgrenade.com/
649•napolux•1d ago•385 comments