Genuine question: What applications/problems it is useful for? Have you seen a good application yet (other than currencies)?
Would love to learn about the positives, from this community.
At it's core, a blockchain is just a really efficient way of guaranteeing the integrity of any given ledger.
I am working on a giftcard purchasing and issuing system at the moment, for example.
I could use a chain of SHA256 hashes of each row hashed upon each previous row of data's SHA256 hash in our MySQL db to make sure that none of my employees were giving themselves an early Christmas bonus if you know what I mean.
Nobody could change any of the giftcard values without being noticed.
Blockchain technology is not only useful for cryptocurrencies.
A “smart contract” is basically an ordinary payment contract where execution steps are gated by separate semaphore controlled by sunsets of the participant set.
What can you do with that? It’s hard to answer without being so general as to be useless, or without getting too specific such that we lose the big picture.
“Block chain” is about replacing courts and arbitration with a computer network, and replacing contract lawyers with programmers. What makes this possible is the fair, untrusted, equal access semaphore a bitcoin spend provides.
seriously, please: tell me one genuine use case for block chains that conventional database stack can't do?
There's literally nothing a blockchain can do that a trusted central database couldn't do. So you only need a blockchain if you can't trust a central database. As a result, the answer to the question you've posed is always going to be a political one, not a technical one. ("It lets banks that don't trust each other keep a shared database of transactions." "It lets citizens who don't trust their various governments exchange currency." "It lets shipping companies that don't trust each other digitize their manifests." "It lets scientists prove their papers were published on a certain date.")
Re your shipping manifest example - can you expand on this - how does this work?
The main point is that, unlike a situation where you would be using a centralized database, there is no need to have a central trusted party to operate the database - the source of trust is distributed among the mining power of all nodes in the network.
If this document is digital, then I might get screwed if you lose stuff or stuff gets damaged and you remove it from the Bill of Lading and say you never saw the goods. Or you might get screwed if I add new stuff to the Bill of Lading after you load the goods and claim you didn't deliver it. So one way to solve this is to put the document and both of our signatures in a blockchain, and now we all agree that this is what we saw on that date.
- Buying contraband
- Ransom payments
- Pump and dump schemes
- Money laundering
Remains to be seen how it will impact the everyday lives of regular people.