Ask HN: What are real-life useful use-cases for blockchain (not currencies)?

The solution solves the exact issue. A claim of fact is sent from one party to another and the blockchain--which is independent of either party's trust--holds that claim including who it was sent from, when, and what the claim was. The only thing it has the potential to not solve is the possibility of the party lying in that claim.

In this specific example, what would they change to photo to? The case is to stop joyrides. Who would be able to take a joyride and end up with the odometer exactly as they had Photoshopped it to hours or days ago?

But yes, depending on the application, photos can be manipulated. But that is stating the problem with using photos, not the timestamping app.

The momentum of an existing mostly-working system. Namecoin is dead but there are a few projects pushing forward, including ENS and Unstoppable Domains.

There's opportunity for a significant privacy and authentication improvement over DNS. Two key advantages:

1. One can run one's own node, reducing or eliminating DNS privacy leakage. Today your ISP can't read your traffic with https://secret-newsletter.example.com/ but they do know that you looked up the IP address of secret-newsletter.example.com. which is about as bad. DoH is somewhat better because you can choose your DoH provider, but in practice people will probably use one of a few major offerings, which they'll have to trust.

2. Info about a name can be authenticated, so in response to query you could receive both the ip address corresponding to a name, and a hash of the TLS certificate that ip address should use, removing the ugly hack of certificate authorities. There's lots of details to get right here, but the potential advantages are enormous.

IMO those are the key advantages of DNS on the blockchain. But there's a big gap between having an idea and executing on it. There's tons of existing DNS infrastructure, and it's not going away overnight, so work is needed for interop, and there are complex questions to resolve around regulation and trademarks etc.

As the saying goes, it takes years to be an overnight success.

Yes, I took great inspiration from HashCash and Proof of Work in general.

Re: minus the refundability

The refundability is the main thing that allowed us to patent this. HashCash, and the large PoW required by Bitcoin are meant to strain any attempt to transact on the respective network. Ours only strains bad callers (monetarily) and does not strain good callers.

The argument we presented was that good/bad callers can be simplified as calls that lasts more/less than some time threshold.

Simple, user-friendly, intuitive, and serves the purpose of disincentivizing high volume spam calls while giving legit unknown callers a chance to bypass the blind filter.

No need to be so snarky.

Could someone tweak the image? Of course. But as a practical concern, probably less than 20 people have the image manipulation skill it would take to do something like this in the ~20 minute handoff period. The transporters certainly don't. This is a bullshit argument, and you know it. And these pictures are not just of the odometer, but the entire car, including the VIN. Photoshopping all of this believably would cost you more than just paying the damages on a joyride. It's a non-issue.

And I think you're misunderstanding something: the issue is not the time before the transporter get custody of the cars, but the many days that the cars are in transit cross-country. If the timestamp didn't exist at the time the transporter starts their journey, the next handoff knows something is up.

As for already trusting us, our clients do, yes, but the point of this solution is to increase the trust-level of custodianship handoff between people who are not our clients. A blockchain is a great solution for this, and a database is simply an inferior solution. And NO, they don't have to trust us to "push the right data on-chain". This logic runs in a very simple SPA and is immediately verifiable on-chain, without using our software, because the blockchain's global state is open.

Yes, it's a bigger problem in these countries, [1] potentially because of the use of multi-country languages spoken by massive numbers of people.

Re: if really you'd want (and could have) something that does the job better.

I'd argue that nothing is better than blockchain in terms of dealing with monetary policy in each country. Since this solution is 100% targeted at the economic incentives that drive phone spam, the reward must be a financial incentive that is easy to globally implement and furthermore allow a user to easily transact with, regardless of country. P2P currencies means someone else in whatever country can worry about designing services that take/use Nano, while I focus on blocking phone spam and don't get wrapped up in potential race/optimization conditions in using "funny money". /rant

Doesn't mean this is a killer app, just as you said, 1 way of trying to solve this 30 year old problem that will only get worse over time as the Internet of Things matures.

[1] https://truecaller.blog/2019/12/03/truecaller-insights-top-2...