Ask HN: How to store large amounts of data on paper with QR code like tech? | Hacker News Reader

Ask HN: How to store large amounts of data on paper with QR code like tech?

20 pointswebmobdev24 comments

An old neighbour wants to settle his affairs - create a will, detail his investments, divide his assets among the kids etc. He asked me if it was possible to create a digital copy of all the documents (will, bank, title deed, investments, online account details etc.) and store it with some QR code like technology so that he can print all of it on a single sheet of paper and hand it to his kids. I remember reading there was some other tech (open source) that could store more data then QR, but I can't seem to recall or find it online. Any suggestions? (Let's not diverge on how there are alternate better solutions like archival disks etc).

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Mind if I ask to what the vision is to have it stored on a QR code on paper?

Reason I ask is because doing it that way is creates some overhead vs just printing plain text on paper. Namely that you'd have to have the format of the QR-like-tech and create and maintain an application to execute the format for whatever current operating system.

So it's creating a bunch of additional work, and I'm not sure what benefit he has in mind.

He feels paper lasts longer than any media (the example he gave was of his record, cassette and CD collections, most of which are unplayable now because of wear and tear or damage :). He wants a digital copy (on paper) as a backup to the physical copies too. I didn't argue or discuss alternate solutions with him because the requirement piqued my curiosity too. I do remember coming across an open source project which was a QR/bar code like tech that could store 2000 or 3000 KB of data. I just can't seem to find it anymore online because I don't recall its name.

Hmmm. And am I correct assuming the reason he'd want to store the data in a QR-like format is so that it can be directly used by a program like Excel? That's the only advantage I can see for using a format over one that can be read by humans directly.

This site has info about QR capacity: https://www.qrcode.com/en/about/version.html

Edit: this is probably the best answer though… https://news.ycombinator.com/item?id=32461230 or the microfiche suggestion… https://news.ycombinator.com/item?id=32462466

I concur, and I'll add that QR codes are mostly useful when you need to quickly transfer a string of data from the analog to the digital world, while also ensuring some data integrity during interpretation.

I can see those complement some human-readable text to minimize manual data input (and the inevitable typo) where required.

Looked into this years ago. 2D barcodes have nowhere near the data density to encode several/multi-page documents that compactly.

But I understand exactly why he wants to do this. 35mm film is commonly available and inexpensive to process. Ilford XP2 would be ideal — black and white film that uses “C41” ordinary color processing.

Set up a stand and lighting, then click away for an hour photographing the printed documents. Send it off and you’ll have a very compact archive result in a few days.

Mount the negatives in slide holders and read with a slide viewer or projector. Or scan with a flatbed or film scanner. Or send them off for 8x10 prints.

This a great a suggestion that will certainly appeal to my neighbour!

Cool!

I wonder if your neighbor is an aficionado of the Alger Hiss / Whitaker Chambers spy saga. A very big deal that no one remembers, but he’s the right vintage to have been captivated by it. The whole thing hinges on microfilm that was hidden in a pumpkin on Chambers’ farm.

Oh, check out this cheap document photo box contraption. No reason it wouldn’t work with a little film camera…

https://www.amazon.com/Scanner-Bin-Document-Scanning-Solutio...

No idea about the spy saga as we are from india (he did tell me about an old tale about an indian spy who went to Pakistan, married some Pakistani, joined the Pakistan Army and managed to rise up the ranks to become an officer before he was finally caught). That scanner bin is a very neat contraption - we could easily make one with a cardboard box at home. I think that, his digital camera or mobile phone and some service like https://www.colorslide.com/ might be a very practical solution for him.

How about zipping pure text or Markdown files, splitting them into QR-code sized chunks (1.5-3KB), converting them to QR-codes and printing all those on a single paper sheet? You can choose their sizes depending on how redundant you want them to be. And restoring them is just doing the same in reverse.

I believe you can fit pretty big texts this way without delving into a rabbit-hole of some obscure formats.

Python app code for decoding that, using existing modules, should fit on a single A4 sheet too without any encoding.

>Any suggestions? (Let's not diverge on how there are alternate better solutions like archival disks etc)

Don't try to do this, not a good idea.

If he wants physical copies that take up less space, the old fashion and time proven way is microfilm. One could probably store a bunch of QR codes on it if you wanted to.

Properly stored film is probably better than paper.

I don’t think a paper sheet can store enough information because of the paper grain. You can actually store a lot of data in a qrcode printed on paper, but not many digitalised documents.

I think he should simply print his documents and give them in a folder. That is not much different than what he wants and people will actually manage to read the documents.

https://blog.codinghorror.com/the-paper-data-storage-option/

Has anybody done the calculation (I'm tempted to, now), if you were to take the text, create QR codes, how much text could you reasonably have on a page? The QRs do have a certain amount of redundancy, which is good. If this is calculated, then how many pages you need is easy.

I am familiar with a product that did this. At 600 dpi we stored 1.8M of data on an A4 page with ~30% ECC codes.

QR codes were not designed for this. To get this reliable there were many image processing, coding and practical issues to solve.

This site suggests a limit of around 100KB per page with standard printer and scanner fidelity: https://www.monperrus.net/martin/store-data-paper

Depending on how long his will is, qr codes might work. A single qr code can store up to 4296 alphanumeric characters, which is about 2.5 pages worth of single space text. This is with a 177x177 cell qr code; not sure how many of those you could reliably fit on a single sheet of paper while maintaining readability but its probably in the double digits, especially if you can print on both sides of the sheet. If you pre-compress the text data, you might be able to get a few hundred pages of text.

https://mbuffett.com/posts/qr-code-hitchhikers-guide/

The only thing I can think of is M-DISC[0] which is designed to last 1000+ years if stored correctly (out of sunlight and extreme temps)

There is also Totenpass[1]. "Totenpass is a permanent digital storage drive made of solid gold"

[0] https://en.wikipedia.org/wiki/M-DISC

[1] https://www.totenpass.com/

I made a small script to securely backup and restore some important files: https://gitlab.com/thexa4/ocrbackup

Data density isn't great though (especially with the added redundancy) but it's enough for things like a password manager file.

Couldn't you use something like Huffman encoding to compress the entire will and print it on a single sheet of paper, then the estate could use OCR to scan and reverse the compression? If you're using ASCII characters only, I assume the compression could be very high.

That's a nice idea. A more user friendly option is preferable though. (Something like - https://blog.codinghorror.com/the-paper-data-storage-option/ ...)

I believe you are thinking of https://ollydbg.de/Paperbak/ which was referenced in the coding horror blog post linked in other comments.

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