People have to keep renewing the contract to pay for those copies though. Afaik there's nothing that guarantees people will maintain them indefinitely after the contract expires.

Yeah that's right, I'm not sure how you could possibly value or incentivize indefinite storage. All storage mediums are consumable and require upkeep, a "one time" pricing model doesn't really make sense.

Arweave (https://www.arweave.org/) is attempting it. Of course, we'll have to wait and see if they're successful.

I would assume that eventually the cost of "old storage" will be too much and new payments wouldn't be able to subsidize it anymore (sort of like a failing Ponzi scheme) but to be fair I haven't heard of this. Thanks for the link!

You're welcome! I have some questions about how the network is going to play out over time wrt mining centralization and access incentivization, but their overall funding model seems sound to me. It's based an endowment that pays out over time to fund storage mining. Their yellow paper (https://www.arweave.org/yellow-paper.pdf) is worth a read if you want to learn about all the details.

And it's still not clear to me how you avoid the situation where a datacenter with 3 network connections masquerades as three different filecoin storage providers with a very similar set of files.

I got curious and looked it up. I found this[0]:

> As the storage miner receives each piece of client data, they place it into a sector. Sectors are the fundamental units of storage in Filecoin, and can contain pieces from multiple deals and clients.

> Next, a process called sealing takes place. During sealing, the sector data is encoded through a sequence of graph and hashing processes to create a unique replica. The encoding process is designed to be slow and computationally heavy, making it difficult to spoof.

[0] https://blog.coinlist.co/deep-dive-into-filecoin/

Oh, so it's secretly proof of work.

I think it's worse than that; it looks like Filecoin's PoRep proves that multiple copies of the data are stored on the same server. I don't understand why this is useful.

There's no incentive to store multiple copies of the same data vs a single copy of multiple datas. It's a possible attack vector, for example you could store all of the copies of some data and then lose it, but there's no economic incentive to do so from what I understand.