| Centralized vs decentralized is not a box to check, there are major costs associated with it. Imagine for instance someone suggesting that a supermarket offers coupons on a distributed ledger. Sounds like a good idea? No, it's dumb. It's dumb because you trust the supermarket to honor the coupon anyway... there's no credible threat model here. OK so we've figured our supermarket coupon system can be run on a centralized database. Well, you suggest, sure we can, but why not just have it decentralized if we can? Because it's expensive. It's expensive in terms of engineering to interface with the blockchain, it's expensive to wait for blockchain confirmations, it's expensive to rely on the non-malevolence of a few mining pools. And did I mention there is about no benefit? However, this is not the most offending use of blockchain technology. You know what, maybe that supermarket gets to federate their coupons to other stores and you can start to see an engineering case. And maybe you're running this in Argentina and there is a credible threat that the government might want to meddle in you coupon scheme, maybe for price control. OK, then maybe you have a case. No, the worse use of blockchain technology is when there is no need for a global mutable singleton. The whole idea of a cryptocurrency is that you need to have an irreversible consensus. This is the crux of the double spending problem, you need to dissipate heat to be irreversible (yes actual heat). This heat could come from "overwriting" your key, but that's hard to prove, so instead Bitcoin uses the heat from the ASIC. I'm simplifying a bit, but this can be made rigorous. However, I've heard many proposals where there is zero need to maintain such a consensus. You mentioned medical records, that's one. People have been talking about running webforums or websites on top of a distributed ledger. Most of those proposals are braindead. |
For instance it can solve the problem of very slow moving governments and allow people to build solutions that might be necessary for the survival of that society then thats actually quite useful to be able to build your own rules that even if they try can' be shut down by a central unit.