Cloud storage is ridiculously convenient when it's working correctly. Anybody who's ever tried it knows that. But cloud storage, at least in its traditional form, also poses a few problems from a consumer perspective.

First, it requires some trust, because you're putting all your data into the hands of some company. You've got to trust and hope that they'll keep it safe, and of course you've also got to hope that they stay in business.

Second, it's often expensive, and you can end up paying for more storage than you actually need, or buying only the bare minimum because you're trying to keep costs down.

Third, it can fail – since your data's stored by a single company and sometimes stored only in a single place, an unexpected problem like a hack or a fire can leave you out of luck. Even something as simple as service downtime can leave you waiting to get access to your stuff for hours.

Sia is a cryptocurrency project that aims to put an end to that by bringing cloud storage onto the blockchain.

The Basics – Sia 101

The basic idea behind Sia is this: people all over the world have tons of internet-connected storage space that they're not using.

Connecting users who need space with users who have space serves both groups, allowing people to monetize their extra storage or store their own stuff securely across a distributed network of other web users' storage. That's what Sia does.

Basically, a user who wants to store their data through Sia gets access to the market of Sia hosts, and they can choose a host or hosts based on bid price. This competitive marketplace ensures that users are getting the lowest available price. Then, the user's files are encrypted and distributed to the user's host or hosts of choice.

In practice, Sia's costs compare very favorably to major cloud competitors like Amazon S3 or Microsoft Azure. 1 TB of storage on either of those platforms will cost you more than $20 a month, whereas the same amount of storage on Sia would cost just over $4.

Almost every aspect of the interchange is customizable and runs trustlessly on the Sia blockchain. The user, for example, can offer uptime incentives to the host. Or they can pick multiple hosts so that they've got redundant backups and won't have to worry about downtime. Whatever agreement the user and the host make is saved in what Sia calls a File Contract, and stored on the immutable blockchain.

Payments are stored in escrow in this contract, and doled out as services are rendered (or returned to the user on an agreed-upon date if services aren't provided as promised).

Siacoin

The cryptocurrency powering Sia transactions is called Siacoin (SC). It's the only currency accepted on the Sia network, and it's designed primarily for use there, but of course it can also be traded independently and even mined.

Sia's blockchain closely mirrors that of Bitcoin, meaning that these days it's mostly mined with specialized ASIC hardware. But unlike Bitcoin, there's a ton of Siacoin out there: more than 33 billion coins as of this writing. That's to keep the price of a single coin low so that it's easier to buy and send small amounts for storage purchases.

Right Here, Right Now

Compared with a lot of other cryptocurrency projects, Sia's biggest selling point might be that it's not just a whitepaper. Its core functionality – distributed storage deals backed by blockchain File Contracts – is already publicly available. There are more than 900 hosts out there on Sia storing over 200 TB of user data.

Some users have complained about bugs in the system, but Sia's being used right here, right now, in the real world. As crazy as it sounds, the fact Sia even has real users and real bugs already puts it ahead of a lot of blockchain projects, which still mostly exist on paper.

Of course, it also has competitors. In addition to the “traditional” giants like Microsoft, Google, and Amazon, there are blockchain-based competitors with similar functionality, like Storj and Maidsafe. But Sia has a significantly larger market cap than any other major blockchain storage player.

It's most significant challenge is likely to be in adoption; improving its UX and UI to make it more competitive with the likes of Google and convincing people that it's a viable alternative to those big, household-name cloud storage companies like Google.

Sia's team is a bit on the young side. The company was co-founded by two 2014 RPI graduates, who are now serving as CEO and and Core Developer. But the company has the backing of venture investors from established firms like Raptor and First Star Ventures, which signals that longtime industry vets have taken a hard look at Sia's product and its team and decided it was worth a bet.