In a classroom you only need a proof of something happening. A separate answer-checking (or even just timestamping) service is a few times easier to create and operate.
> A separate [...] service is a few times easier to create and operate
Because it relies on trust in the service. Blockchains don't. You can run a validation regime for anything you want on a blockchain: legal, illegal, anonymous, public, anything. Store any data you want and you can verify for all of posterity that it was stored before the block timestamp.
That's the feature, anyway. But you're right, in practice (1) it's generally trivial to find a trusted service for what you want to do (trust is cheap for almost everything) and (2) actually implementing this kind of thing on a blockchain is a huge mess (bitcoin et. al. are EXTREMELY expensive vs. just trusting someone).
Maybe (2) will be addressed at some point by improved technology. But really (1) is the thing that makes this a failing proposition. Libertarian fantasy-spinning notwithstanding, the only people who really need the blockchain are doing shit the rest of us don't want them to do.
Except they do. Blockchains rely on a majority of actors not getting together to commit fraud. This is somewhat reasonable but still a real concern at the kind of scale Bitcoin has; getting 51% of the children in a class to gang up on someone for the lolz is trivial.
They rely on the mechanism which converts from physical to digital being reliable and trusted. Vaccine passports on a blockchain provide exactly 0 assurance that the pharmacist wasn't bribed.
They rely on the blockchain software being free from bugs and no-one-but-us trapdoors. Ask the OpenSSL community how easy verifying crypto code is.
Blockchains are not a magic solution to all trust problems.
Because it relies on trust in the service. Blockchains don't. You can run a validation regime for anything you want on a blockchain: legal, illegal, anonymous, public, anything. Store any data you want and you can verify for all of posterity that it was stored before the block timestamp.
That's the feature, anyway. But you're right, in practice (1) it's generally trivial to find a trusted service for what you want to do (trust is cheap for almost everything) and (2) actually implementing this kind of thing on a blockchain is a huge mess (bitcoin et. al. are EXTREMELY expensive vs. just trusting someone).
Maybe (2) will be addressed at some point by improved technology. But really (1) is the thing that makes this a failing proposition. Libertarian fantasy-spinning notwithstanding, the only people who really need the blockchain are doing shit the rest of us don't want them to do.