The problem with all these privacy preserving cryptographic breakthroughs is they are never deployed in practice.
Just look at cryptocurrency. We've known how to create a privacy preserving, truly distributed, cryptographic replacement to cash for decades, and what we end up with instead is Bitcoin and the like, which is pseudo-anonymous only and ends up being centralised anyway to interact with the fiat world.
Theres no demand for this tech in current society.
David Chaum [1], a famous Cryptographer, founded International association of Cryptologic Research (IACR). He published so many articles on digital-cash, anonymous cash, etc. He had patents on them; he even founded a company on that concept. However, that company failed.
blind signatures are nice and verifiably unlinkable but digital bearer certificates require a trusted central "mint" to issue and reissue them. This central point of failure can and inevitably will... fail, as Chaum's company (Digicash) did. And it can also inflate the currency without anyone knowing.
Bitcoin was the result of cypherpunks going back to the drawing board to create a decentralized solution. Unfortunately bitcoin sacrificed unlinkability for decentralization. Modern "privacy" cryptocurrencies utilizing zero-knowledge proofs are advancing the state-of-the-art in terms of having both properties.
A decentralized DBC "mint" is theoretically possible. However there are two more downsides to blind signature approach: (1) auditing is impossible because there is no history so detecting if mint-node(s) have colluded to cheat or catching an inflation bug is unsolved problem. (2) Arbitrary amounts are not supported so it is necessary to create fixed denomination "notes", which then add size and complexity to every transaction.
source: been there, done that. bought the t-shirt.
That's not true. Sometimes these technologies get pulled up high side or are only developed there so the public doesn't hear about them. You should read the ietf paper on the crypto wars. Crypto and ZKPs are some of the known attempts to keep these technologies out of the public.
Just look at cryptocurrency. We've known how to create a privacy preserving, truly distributed, cryptographic replacement to cash for decades, and what we end up with instead is Bitcoin and the like, which is pseudo-anonymous only and ends up being centralised anyway to interact with the fiat world.
Theres no demand for this tech in current society.
Sigh