Topic: [Serious] How long does the paper in a casascius stay legible? (Read 1067 times)

Not a direct answer to your question but I made a list of problems I had with other often-used cold storage methods: https://bitcointalksearch.org/topic/whats-wrong-with-my-current-cold-storage-weaknesses-in-cold-storage-methods-1634293


I would assume it will break down over time but keeping it sealed and out of light and heat should make it last a lot longer.

Its an almost unanswerable question. We wont know how long they will last until they are no longer lasting ...

Need to understand paper and ink used by Mike, then draw parallels from the nearest equivalents

Interesting to know if the holos provide an air tight enclosure (and even if they block light)

Clearly having in an airtite or ANACS slab would assist, and keeping them in a slab case that blocks the light

I agree decades should be achievable, if not longer, given some old notes / maps ages

Has Mike himself made a statement on the subject? So far all that's been discussed on the topic has been hearsay, correct?

I had the same impression but others on here may know more.

I would imagine that if left untouched and out of direct sunlight the private key on the back would be legible for decades, no?

Most retail receipt are printed on thermal paper, the printer is an array of small heat emitters which the paper pass through, when thermal paper is subjected to heat then will it turn black. It is a commonly known that the print will not last much more than a year. Perfect for retail as it is cheap and reliable, and any warranty proff would be more or less gone after a year. Totally nogo for private keys.

How many coins do you have with receipt paper that was used in them?

thanks!

Is there a consensus on which paper is the best to print a private key with?  

I noticed AT101ET mentioned "acid free paper" which may be better than the standard laser office paper.  I've made a couple DIY coins and wouldn't mind picking up some better paper for my laser printer for keys under holograms.

I have a couple of redeemed Casascius coins, complete with peeled holo + paper with private key.
I have inspected the private keys with a magnifier, no signs of deterioration or any other damage at this point.

Someone send me one of those 1000BTC coins and I'll watch until I can't read it anymore . Sound good? I guess I could try it with a 10BTC coin too... But that would be much less erm.. Scientific shall we say? I'm MUCH more curious about the 1000BTC coins

Good question, as others have said, store them well and I'm sure they'll last a long time.

Store it correctly and you shouldnt have a problem, good question though.

I still have several mistake v1's and the paper disc is still readable.

If I were a smart enough criminal to used the solvent described in that article I'd have to assume that criminal would be smart enough not to take the money right away. That way everyone would know it was you rather than there being a 1/2 or 1/10 chance it was you. The only proof would be the only people who owned the coins in the past or future's (up until you steal them) word. This could happen with any physical bitcoin in a few years. Someone's going to be left holding the beg and the person to blame will be the coin maker.

That's why you should ways check the address on the coin via uberbills or the blockchain. Unless they replace the publickey with another existing 25btc key, which will get unnoticed until the original owner of the coin with that specific public key finds out.

Huh. Really makes you think, why would I want another possible way to get my bitcoins hacked? A physical hack would be a lot cheaper and could go undetected for a while. Let's say I bought a 25BTC coin, opened it up with their method and recirculated it by selling it. After a few years and a few different owners I could sweep the address and no one would know for sure who did it. That's just terrifying!!

Back on topic though, you'd have to find out exactly what make/model of printer he used to print the private keys. From their you could find out from the manufacturers website or google how long they would actually last.

I have done a little research into what ways of printing tends to last the longest.  Laser printers are effective for longer term archival purposes because it is essentially baking a layer of plastic (toner) onto the paper, which is why the paper is warm when it comes out. As a result, laser ink would does not easily deteriorate or fade.  An inkjet printer, on the other hand, sprays tiny droplets of liquid ink onto paper. Inkjet ink would be less resistant to moisture because it could bleed or run if the ink doesn't stay dry.  However, higher quality ink and paper can help reduce that risk.

There are also thermal printers which uses heat-sensitive paper and selectively transfers an image to the sheet.  One example of a thermal printer used for bitcoin is the Piper wallet, which is essentially a Raspberry Pi hooked up to a thermal printer.  According to their FAQ, the image will last 20 years when stored in typical office filing conditions (In a cool, dry environment with no exposure to light).
http://cryptographi.com/pages/piper-faq
. We probably have all observed receipts fading to the point of being nearly unreadable within a year or so.  Piper wallet uses a higher quality thermal paper so it's different than what you would get as a receipt from a store, but would still not be ideal for long term storage given the other options.

As with all things, whether you use Laser, Inkjet, or Thermal, the quality of the ink and paper matter greatly, as well as the conditions in which the paper is kept.  Given that a private key on a physical bitcoin is going to be printed on a laser or inkjet printer, sealed under a hologram, and the coin stored in a plastic airtite case, flip, or slab, it would be reasonable to expect that any coin that does not get exposed to high level of moisture or temperature extremes would, at a minimum, last 80-100 years.  If the maker uses high quality paper and ink/toner, then it should last much longer. 

That is the worst thing i have heard/read so far. So it should be like either buy from original maker or otherwise dont peel them , just keep'em circulating

There are much cheaper ways to compromise the key on a physical Bitcoin.  Tamper-evident holograms only keep honest people honest.

http://www.coindesk.com/defcon-hackers-crack-physical-bitcoin-casascius-coins/

usually only thermo print... that does not last long time.