Blockchain, as in a decentralized ledger that is extremely difficult to tamper with, is not in theory tied to cryptocurrency, but the only currently known way to do it is with cryptocurrency. It might be possible to do it another way but it would require a theoretical breakthrough.
Now just to break down what this is in its purest form, is the basic idea that you have a long list of entries that include a hash of all the previous entries (and I'd assume all the previous entries and itself as well) using a deliberately inefficient and slow hashing algorithm for the explicit purpose of making it cost prohibitive to create an altered version, but then there'd have to be some more efficient way to quickly verify that as well so is it some particularly weird and clever method that makes it hard to generate but easy to verify? And then that just gets mirrored across a bunch of hosts via some networking scheme that works on consensus, to further confound attempts to introduce falsified records?
The big question then is why? It's trustless record keeping, but you still have to trust whatever is creating the entries and you have to trust whatever will honor the entries, which are all much bigger problems than preserving an untampered-with database. Like what is an actual use case that would benefit specifically from creating a database that can't be altered enough to offset the cost of making it expensive to alter or even write to in the first place?
imagine getting a socialist paradise, where you no longer have to pay $250 to your medical insurance to see your doctor, but instead you have to pay $250 in energy costs to validate your medical records hash
The database doesn't have to be expensive to alter, that's a consequence of one particular type of scheme, proof of work, and there are already good alternatives or there will be shortly, with more coming. For use cases of a trustless distributed computer/database, see my other comment.
Blockchain, as in a decentralized ledger that is extremely difficult to tamper with, is not in theory tied to cryptocurrency, but the only currently known way to do it is with cryptocurrency. It might be possible to do it another way but it would require a theoretical breakthrough.
Now just to break down what this is in its purest form, is the basic idea that you have a long list of entries that include a hash of all the previous entries (and I'd assume all the previous entries and itself as well) using a deliberately inefficient and slow hashing algorithm for the explicit purpose of making it cost prohibitive to create an altered version, but then there'd have to be some more efficient way to quickly verify that as well so is it some particularly weird and clever method that makes it hard to generate but easy to verify? And then that just gets mirrored across a bunch of hosts via some networking scheme that works on consensus, to further confound attempts to introduce falsified records?
The big question then is why? It's trustless record keeping, but you still have to trust whatever is creating the entries and you have to trust whatever will honor the entries, which are all much bigger problems than preserving an untampered-with database. Like what is an actual use case that would benefit specifically from creating a database that can't be altered enough to offset the cost of making it expensive to alter or even write to in the first place?
imagine getting a socialist paradise, where you no longer have to pay $250 to your medical insurance to see your doctor, but instead you have to pay $250 in energy costs to validate your medical records hash
Thanks for this it’s genuinely helpful.
The database doesn't have to be expensive to alter, that's a consequence of one particular type of scheme, proof of work, and there are already good alternatives or there will be shortly, with more coming. For use cases of a trustless distributed computer/database, see my other comment.