The blockchain adds nothing useful to the setup, you could have the exact same level of confidence if each link in the chain e-mailed a photo to a central inbox.
You just described a blockchain. Why rebuild what already exists? A blockchain is a great drop-in solution and reduces our costs and implementation worries massively. And the distribution of this public blockchain is much more decentralized than we could ever achieve running our own nodes.
I purposefully did not describe a blockchain, although that depends on what your definition of blockchain is.
If we're defining blockchain as something descending from Satoshi's 2008 paper, then what I described is not a blockchain.
The distinction I'm making is one of trust. I was describing a database with centralized trust.
> Why rebuild what already exists? A blockchain is a great drop-in solution and reduces our costs and implementation worries massively.
I didn't say you should rebuild anything.
It sounds like you think that the only easy-to-use, mature append-only databases with cryptographically verifiable logs (popularly called "ledger databases" these days) are blockchains. That's not true. All the major clouds have such databases now.
> And the distribution of this public blockchain is much more decentralized than we could ever achieve running our own nodes.
I still don't see any evidence (either from you or anyone else advocating blockchains) that this is good for you use case.
Can you please explain an attack that is possible against something like Amazon's QLDB[1] but is impossible against a public blockchain?
There's also the issue of speed and usage costs of public blockchains, not to mention the frequent bugs, 51% attacks, and other uncertainties that come up.
We know the costs of building on public blockchains. I'm dying for someone to come up with a benefit that is only possible on that blockchain. Every time they try, it seems to be benefits that are shared with services like QLDB or a variety of FOSS solutions.
1. https://docs.aws.amazon.com/qldb/latest/developerguide/verif...
People made insane money with Bitcoin, Ethereum and others. People then dropped lots of other "coins" that eventually no one cared about. "Blockchain as useful technology" is the story to sell the next "coin". Employing a couple of devs and funding a few blockchain startups is trivial money in this context, often sponsored by "believers" (who got rich in the early days)
Blockchain tech comes with inescapable complexities and problems: bugs and security issues can't be fixed in blockchain programs. Any trivial action on the blockchain requires mining, i.e. the very thing that's done with specialized hardware in areas where energy is cheap.
My last point seems to be tangential, but do try it yourself with a small project on a private Ethereum chain, using geth, web3.js, there are good tutorials out there. Usually when you try out a fancy new tech you "get it" after a while, but I definitively did NOT see any way this is feasible.