Excuse my ignorance but I was always under the impression that Siacoins would be mined
with proof of storage. So we are using proof of work like Bitcoin to mine? And proof of storage is only for renting storage?
That's correct.
A pure proof-of-storage solution was what we had in mind when we set out to build Sia. However, the problem is much thornier than it appears. It's easy to hand-wave and say "easy, just use Byzantine Paxos!" but the truth is cryptosystems are extremely difficult to get right, both in theory and implementation. After working on proof-of-storage for close to a year, we were still grappling with a number of theoretical problems, and the implementation had grown unacceptably complex with no end in sight. I don't believe these problems are completely intractable, but it's important to keep in mind that they must be solved in a
practical context where things like complexity, efficiency, and attack surface are just as important as the theoretical solution itself. (Taek can give you more details if you're interested.)
So we made the difficult decision to scrap it all and start over with a proof-of-work blockchain, which remains the only real "tried and true" cryptocurrency consensus algorithm in widespread use today. We are a bit disappointed that we had to make the switch, but ultimately our goal was (and is) distributed storage, not proof-of-storage-based consensus. By building on top of the solid theoretical base that the blockchain provides, we can focus on the storage aspect without worrying about someone discovering a theoretical attack on proof-of-storage and sabotaging the network.
So are there details as to what is needed to mine? Cpu power? Is it pointless to mine on a laptop?
Our hashing algorithm is BLAKE2, which (to my knowledge) has GPU miner implementations, but no ASICs yet. Still, mining on a laptop probably won't be very fruitful. If you're lucky you might mine a block or two immediately after launch.
This is promising. I like the idea and it has real world utility. In the world of cloud storage though, what benefits would users have using decentralised storage? P2P like torrent already presents some form of meaningful 'storage' already, and is ubiquitous technology.
Sia is very torrent-like, in that you can download from multiple peers simultaneously. The difference is the introduction of cryptocurrency. If you squint, you can view Sia as a means of incentivizing people to "seed" your "torrents." The reason no one stores their personal data on a torrent is that there's no guarantee that people will seed it. The closest we have is private trackers with "seeding points", "upload credit", etc. Sia gives you much stronger guarantees that people will retain your data, and better ways to manage the risk associated with P2P cloud storage (e.g. encryption, erasure coding).