Hah, I just thought of a legit use for OMG BLOCKCHAIN.
I've idly wanted some sort of public timestamp assertion server for a while. Like https://tools.ietf.org/html/rfc3161 ... except I'd rather not rely on a trusted third party that might decide to just shut down at some point.
Piggy-backing on a Bitcoin-like blockchain (even Bitcoin itself) seems like a good solution.
I know Bitcoin transactions can carry comments, need to read up on whether they are covered by the transaction/block signature.
... the use-case I currently have for this, is of course, accounting.
I'd like to make assertions about the source documents in my home-grown accounting system, that prove they haven't been fiddled with after they were saved to disk.
If I get something like the Bitcoin blockchain to do that for me, I'll arguably have stronger integrity on my home-grown bookkeeping than many medium-sized businesses with professional accounting software.
That seems like a really neat property.
This idea of mine is so original it already has a Wikipedia page! https://en.wikipedia.org/wiki/Trusted_timestamping
... but no mention of any Blockchain-based implementations.
Oh shit, another side-project! Maybe if I hide it won't find me.
@HerraBRE Just put the hashes on your personal Wikipedia page or in a Github gist? They'll timestamp them for you in the history. Perhaps the Icelandic or Italian tax authorities will accept that you don't have power of either of those.
@edavies That works. I just like the elegance of a solution that doesn't rely on an authority.
I mean, I could also just tweet the hashes. Or toot them.
But the Blockchain does really provide stronger assurances here, and it is a public, available service I can use. I can even take my pick, BTC, BCH, LTC, ZEC... they can all do this.
For example, although I may not be granted access to edit the history in some of those cases... I can delete the accounts and make the evidence disappear.
@HerraBRE Yes, I was being a bit tongue in cheek. Still, I'd bet on Wikipedia over Bitcoin for longevity.
But it could work. Have done it before (2011) for an internet 'bet'. Can't remember the details now, to be honest. https://en.wikipedia.org/wiki/User:EdDavies
@HerraBRE Doesn't Bitcoin have an authority, though? It's just that it's very widely distributed and easy to check so unlikely to be suborned. The question, then, is how unlikely you need for your purposes.
But, yes, it would be nice to have a general solution.
@edavies Bitcoin (etc) provides the property of authority, but no entity or fixed group of entities is "the authority."
There is no individual or group you can bribe or threaten or cajole.
Also, the data structure is immutable, unlike a wiki or git log or Twitter account, which can all be rewritten if you have/hack/buy/force the right access.
It really is very different. My use case arguably doesn't need such strong guarantees, but if they're available for cheap/free... why not use 'em?
