Fundamentals
This page is designed to introduce you to what Sia is, how it works and how you can use it. Get ready, it won't be short - the aim here is to explain all the basics in a single place so you don't get lost. So take your time and feel free to use the navigation menu on right to jump quickly between sections.
Why should I even read this?
Your entire online presence depends completely on others. When services get offline or shut down you're losing parts of yourself and can do nothing about it because there are no better alternatives that would put you in control. And it's even worse if it's source of your income.
Do you want to know if there is a way to change this? And can it even work at scale? We won't tell you - start reading and make your own judgement.
Don't trust, verify.
What is Sia?
Sia is a - private decentralized cloud storage network - without a single point of failure. You can think of it as of a global hard drive that keeps your data distributed among many hosts around the globe.
You can use it for:
renting- You pay for uploads and access to your data.hosting- You provide your unused space to others and get paid for it.
You can also use it indirectly thanks to third party products built with Sia. Seemingly there might be no difference, but in the background they run the renting software, allowing them to be cheaper and geo-redundant by default.
Decentralized storage is not limited to decentralized users, anyone can use it.
It is open-source and anyone can use it without any permission and in any way - there are no restrictions of what you can or cannot do.
How does it work?
No trust is required
Anyone can run the downloaded or compiled software to become a part of the network where everyone keeps track of the consensus - a state of the network with all of its transactions and file contracts that all network participants agree with.
This creates an environment where you always have the correct data with no trust required - your software doesn't trust anyone and verifies everything.
The consensus is needed to ensure that file contracts between hosts and renters are properly settled - to make sure that renters pay for the service and hosts get paid only if they kept their promise.
This is accomplished by the file contracts in whose the renters lock so called allowance - an amount of funds based on the estimated storage use and hosts then lock in roughly twice as much as so called collateral.
If hosts don't keep their promise, they lose the collateral and renter will automatically re-construct and re-upload affected pieces of data to another host. In the end, host gets paid only for the actually used storage and bandwidth - remaining funds will return to the renter.
Your files are secure
By default, your files are not only encrypted, but also stored with 3x redundancy. Sia is using erasure coding where each file is encrypted and split into 30 unique pieces but you only need any 10 of them to retrieve your data.
Whenever the host holding a specific piece of your file goes offline for too long, that piece is reconstructed (which is easy by using the other pieces) and re-uploaded to a new host. Sia software keeps track of your file health and handles this automatically.
Price for freedom
Storage pricing is roughly $3 per TB per Month but keep in mind that it depends on individual hosts, the developers of Sia software don't sell any storage.
Hosts provide their storage in order to earn money. Running a host requires investment into the hardware and connection and you're competing with other hosts which has an auto-balancing effect on price, making it fair for both, hosts and renters.
However, hosts are not equal. Some may provide higher quality for higher price and some may provide lower quality for cheap, because they just provide excess storage on a machine that runs 24/7 anyway.