Cryptocurrencies have not actually invented much new technology, they mostly combined existing ideas in new ways. Merkel trees, for example, are an almost 50 year old idea, zero-knowledge proofs are almost 40 years old, proof of work predates Bitcoin by 15 years which makes it 30 years old.
I think the initial impractical prototypes for the core techniques were in the literature for a while but there's really no comparison between eg interactive ZK protocols and the succinct non-interactive proofs used by the cryptocurrency folks. The latter are computationally general (you don't have to roll a new one for each program) and many orders of magnitude more efficient.
I think it's important to give the cryptocurrency industry credit for the few corners in which it makes real (theory/tooling) contributions even if they're motivated by nonsense
I did not want to say that they invented or improved nothing, just that a lot of the building blocks already existed. I just looked this up, non-interactive zero-knowledge proof also seem to have a history back to the late 80s, but if cryptocurrencies gave us some improvements and new ideas that made them more practical, fine, I am not going to complain about that.
You can do general purpose programming in all kinds of DSLs and Rust libraries that compiles down to big-but-practical arithmetic circuits and then generate proofs that y=f(x) without revealing x for arbitrary f. That really wasn't possible until a few years ago and emerged almost exclusively within the sphere of cryptocurrency-adjacent research. You can also use the succinctness of SNARKs to batch these proofs and shrink the verifier costs to almost nothing
It's a cool model for asymmetric computing, with low capacity verifiers collecting results from high capacity provers. It'll probably find uses outside deranged gambling...
> I think you'll see people picking those techniques
Those techniques were already invented and in-use long beforehand though.
I think that needs emphasizing, because sometimes it feels like... Imagine that fans of the Segway claimed it will replace all other forms of transportation, and a worrying number of them are still out there crediting the (failing) product for inventing the wheel.
The way I see it, "blockchain" (NFTs, etc) are less technologies and more business-plans to make money--perhaps in a slightly more-literal sense than usual--from available tools.
It's kind of like ride-share services: They didn't invent cars or databases or dispatching systems or phone-apps, and while their investment might have spurred some new tools/libraries/algorithms they use, the broader usefulness of those inventions doesn't flow backward to mean they have a good/sustainable business.
There are even cases like "private blockchain" where the fad-marketing is getting used to mislabel what is actually just a regular old distributed database of yesteryear.