I’m working on a project what requires around 1 to 2kb of data to be stored for ~80 years.
My thinking was a QR code (ECC H) etched into aluminium. Benefits being no bit rot & the assumption being cameras should still be commonplace in 80 years (And if QR isn’t a commonly used format anymore, surely an AI agent could easily write an app for the user).
Does anyone have any better suggestions or think I’ve missed anything.
If cameras are still around why not just write out the text on a metal tape, like aluminum foil, with holes where ink would be if printed. That way, the encoding (QR or whatever) is not the issue.
There’s some kind of glass based storage which will last centuries, but it’s kind of bad against scratching, so that’s something to worry about. I believe Microsoft was building a data center with it somewhere.
Best case: Accessible technology for the common human not costing a whole r&d lab.
Tape for example is cheap but would you really want to spend >5k€ on a drive for a one-off backup?
acid free archival paper. archival ink. Even non archival books can last quite awhile I personally own a book that is over 120 years old. Don’t sleep on books.
No, you’ll fuck your back up.
But, seriously, it is amazing. When I was a kid the school had an already very old computer that could run the BBC Domesday Project, a mid-1980s snapshot of life in the UK using the latest (for the time) multimedia technology, which included a bespoke LaserDisc player. By the time I used it, it was already failing and by the early naughts it was essentially lost media, with virtually no working hardware left and the Laserdiscs themselves starting to perish with age. Meanwhile, the original Domesday manuscript - written in the 1086 IIRC - still exists: coddled, protected and safe, but still there.
Reminds me of “carving words into stone” but that message was supposed to last 15 million years so… aluminium sounds good for 80. Can you fit 2kb in a QR code ? do they even have an upper limit ?
What kind of data is it? If it can be printed, you can just print it and store it somewhere safe, or print multiple copies and distribute it around. Plenty of 80 year old books are perfectly readable. That’d only be books printed in 1946 so nothing crazy. You can pay for professional printing so they can do it on good quality paper and so on.
Plate of stainless (the non rusting kind) and laser cut a QR like code through it like a stencil. If they can’t get a good read on the plate with a camera, you can lay the plate down on paper and spray or dab stencil paint through the holes to form a flat image on paper of your QR

Do a job so bad no one ever ever ever forgets about it.
Hey it’s good quality copper, you must be using it wrong.
So what Trump is doing
2kb is about 4 double spaced pages. Why not just write it out and store copies in multiple locations?
1 to 2 Kb isn’t all that much. Write it down on acid free paper. Use plain ink with a good binder, neutral pH, UV resistance is generally optional in this case, but better. Better safe than sorry. Store it away from light in low humidity at temps <16 deg C. Seal hermetically. Use oxygen absorbers.
And laminate maybe
You might be looking at the wrong thing. The problem isn’t likely to be the medium over that time period, it’s much more likely to be the perception of the value and use of the thing.
I have 100+ year old records, furniture, art, electronics, documents etc. a few were built to last but most are normal consumer grade stuff from times before.
They are still kicking around not because of their uniquely good quality or archival construction but because someone before me thought to keep ahold of them.
So you probably have three new problems to solve: how to get your message on something that people won’t just throw out, how to get it on as much stuff as possible to minimize the changes it’ll be thrown out and what format will actually be recognized as an indicator of something worth investigating as opposed to just another dead link to a Chinese user manual.
80 or less?
anything? hell, a piece of paper will last less than 80 years
The devil is indeed in the details, thank you Lucifer.
Specifically, I would look for “archival paper,” which is made for exactly this purpose.
Interesting, will investigate!
Etching aluminium might not photograph with enough contrast to pull out the QR code.
Laser etching glass might be worth a look. You can increase the contrast fairly dramatically with black paint, which can be cleaned and reapplied without damaging the glass.
Is it 1-2kB uncompressed? Because compression will help, the smaller you get the data the larger you can make the QR pixels. You can also split it into 20x100B chunks, and then as long as you number the slides you can rebuild later.
Also, ecc-h only gets you 30% recovery, duplicate or triplicate slides could increase that even further.
I mean you can take a picture and increase contrast. Coat the aluminum black before etching too
Coating would work, but it needs to be permanent, because you can’t easily recoat it. Glass can be recoated on the other side. Dunno how anodising and etching would work, do you get the same color when you etch, or do you get raw aluminium?
I suppose if you scanned the plates in a flatbed scanner that might be even contrast, I was thinking of using a phone camera, and assumed it would be near impossible to get an even lighting across the QR code.
Very interesting, thank you for the advice!
Glass is super underrated for this application because it has the stigma of shattering but high tensile glass with laser etching would last millions of years without degrading.
2kb, by what coding, but just good quality paper? would require few pages. Possibly protect it by good cover, box, vacuum air off.
We have over 2000yo scrolls, so 80y should be ez with good materials.
Note, that most modern materials are intended to last few years only, get good quality paper and ink, if printing, use bigger font.
if properly processed and stored, good old silver halide film is rated to last hundreds of years. it’s also waterproof! your choice for how the data is encoded on it.
I actually think there’s two facets at play here. There’s the first dimension, the durability of the medium itself against the environment, which is what you’re asking about. The second dimension is redundancy. It’s all well and good if you invest in aluminum but something heavy gets dropped on your plate and the singular copy is damaged beyond recovery. Worth considering that if this information is important enough to etch in metal, you should make several copies across a few different storage mediums in a handful of physical locations. A safe deposit box may not be a bad idea, for example.
He’s also assuming whatever format he picks will be readable without including a reader or instructions in the box.
There’s a possible option to engrave instructions on the back, but I get what you mean















