About Sia

Sia is a trustless, decentralized platform built with the intention of allowing users to maintain control of their data. Unlike traditional cloud storage providers, the Sia protocol is blind to what data is stored on it, and the design of Sia contracts mean that price and duration of your storage agreement cannot change once locked in. You don't risk losing your data because a company decides it's objectionable, or because of an increase in price halfway through the storage term.

To date, Sia is the only storage platform that is truly decentralized - there is no third party that has the ability to modify storage contracts or erase your data. All agreements are controlled between the renter, the host(s), the decentralized autonomous network, and the blockchain. Another benefit of Sia is that it's significantly cheaper than traditional cloud-based storage solutions, but with comparable uptime and fault tolerance characteristics.

Sia allows anyone with spare hard drive space to rent it out on the Sia network. Anybody anywhere in the world can add their storage to the Sia network, and get paid to do so. On the renter end, Sia is ultimately intended for enterprise use in a manner similar to that in which Amazon S3 is used today, but anybody can also rent space on the network. At scale, it could be an effective, geologically distributed Content Distribution Network (CDN), though the project is still in relatively early stages today.

A common misconception is that Sia is trying to be "another Dropbox", which is not accurate. Sia aims to be the back-end storage provider that other applications and services such as Dropbox would use. If Sia achieves it's goal of capturing a large share of the massive cloud storage market, most end users won't be aware of Sia any more than they are aware of services like Amazon S3 or Microsoft Azure being the foundation of the websites and applications they use.

The Sia Network

The network connects renters and hosts to each other, and keeps track of storage contracts.

The Sia-UI Client v1.5.0 on Windows.

On the Sia network, a renter is someone who is paying to rent storage; a host is someone with excess storage space who elects to rent it out on the Sia network. You can be a renter, a host, or both at the same time on the Sia network. You can also simply use a Sia client as a wallet if you don't want to rent or host, or use Skynet to upload and share files at no cost.

Sia Clients: Sia-UI, siac and siad

The Sia network is comprised of the Sia client running on several computers. The client is available in a UI version called Sia-UI, as well as via command line via a utility called siac. The Sia daemon, siad is what actually runs in the background, and what the Sia-UI and siac interact with. siad can also be accessed through REST API calls using a utility like curl. The Sia client serves several functions: a wallet for Siacoins, and an interface for renters and hosts to buy and sell data and upload or download files to Sia or Skynet.

The Sia client allows renters and hosts to interact with each other by creating storage contracts. Renters can specify how much money, in Siacoins, they wish to spend on storage; hosts can specify storage prices and a number of other values that affect their probability of being selected for a contract. More information on renting and hosting can be found in the Renting and Hosting sections of this site.

Note that the Sia-UI client (as in the GUI version of Sia specifically) is often frustrating to use, because it often does not make it clear what the status of the Sia daemon is or what is going on in the background, is often unresponsive, can take hours or even days to synchronize, and has other issues like input and output formatting within the Sia-UI Terminal where manual commands can be entered to configure certain settings or troubleshoot items. If you are comfortable with using command line tools and you don't need a GUI, your experience with Sia will likely be better by using siac and siad directly instead.

Skynet

Skynet is a new component of the Sia network which allows users to publicly share content stored on Sia. Skynet was announced in February 2020, and is touted as "changing the internet forever" by the Sia team, though we at SiaSetup believe that to be a bit of an overstatement and an ambitious goal.

Along with using standard Sia storage similar to normal renting and hosting, Skynet introduces public websites called Portals which provide an interface between the Sia storage network and the public Internet in order to allow users to access and share files stored on Sia without needing to use a Sia client. Skynet also has a focus on building client-side Skynet Apps, called "Skapps", which run in a user's browser and do not require central services from traditional servers, in order to build distributed and decentralized Skapps which can run through any Portal. However, normal content on Skynet is immutable, and the only mutable form of storage is a key-value store called SkyDB which is more comparable to Redis software than a traditional database like SQL - so Skapps are limited in functionality and must be constructed a certain way for Skynet.

More information on Skynet can be found in our Skynet section.

Sia Blockchain and Cryptocurrency

Another large component of the Sia network is the Sia blockchain and cryptocurrency Siacoin, which is further discussed in Siacoins and Siafunds. The blockchain is responsible for managing storage contracts, as well as providing a means by which transactions between users can occur. The blockchain does not store renter data - if you rent storage space on Sia, it will be space on host computers. In regards to storing data, the blockchain is only used to manage the contracts and payments for the agreement of storing renter data on host machines.

How Data is Stored

Encrypted, distributed, redundant data storage is the highlight of the primary Sia network.

Normal Sia Data

When a renter creates a storage contract via the Sia-UI and begins to upload their data, Sia encrypts and breaks apart the data into pieces and distributes it to multiple hosts (currently 30, using default settings). The data is broken apart with the use of an algorithm called Reed-Solomon codes, to a level of 3x redundancy. This means that only 10 pieces of the original 30 are needed in order to reconstruct the data. This allows up to 20 of the 30 hosts to go offline or lose the data, and the data will still be accessible. If your hosts are online 90% of the time, this results in over 99.99% overall uptime of data stored on the Sia network.

Normal Sia renter data is encrypted and split into pieces by default, so hosts have no way of accessing a private renter's data, or even being able to determine what type of data they're storing. The renter can feel secure in knowing that only they have access to their data, and the host is protected from liability for any data they store because it is impossible for the host to know anything about the data. Hosts are also incentiviced to stay online and retain data via a number of host scoring metrics.

Skynet Data

Skynet data, on the other hand, is stored in one piece on each host and unencrypted by default. It is stored with 10x redundancy by default across multiple hosts. The logic behind storing the data unencrypted is that Skynet is intended to be used for files which are shared publicly with others, such as assets for public websites, shared media, and other material which is not inherently private. These files are also stored on normal Sia hosts - because there is currently no way for hosts to decline only Skynet data, hosts with liability concerns about storing unencrypted data in one piece may wish to avoid hosting on Sia until this is changed. More information on why host liability may be increased due to Skynet can be found on the Hosting page.

Sia Foundation Proposal and Changes

A proposal is in the works to split core Sia development and Skynet development into two entities.

In September 2020, a proposal was put forth to create a nonprofit organization called the Sia Foundation. The Foundation proposal can be viewed here, and in short, it proposes:

• A registered nonprofit organization called the Sia Foundation to be created, initially consisting of Sia co-founder Luke Champine and Luxor tech head Eddie Wang as board members
• An initial 1.6 billion SC lump sum to fund the Foundation
• A 30,000 SC/block Foundation fee to be added to Sia in order to continue to fund Foundation initiatives (about 1.5 billion SC/year)
• Selling of the Sia IP (i.e. the Sia name and logo) to the Foundation for approximately $1 million USD
• Shifting of core Sia protocol development to the Sia Foundation
• Creation of a number of Foundation budgets and grants to fund community services (like SiaSetup), Skynet Portals, hackathons, and a legal fund
• Rebranding Nebulous Labs as Skynet Labs, which would then focus on Skynet development, and possibly also some renter and host development

Proposal Reception

Overall, community support of the proposal was initially good due to the focus on supporting community initiatives throughout the Sia ecosystem. Nebulous privately reached out to several "prominent" community members in advance with a draft of the proposal, allowing them to provide feedback and try to get everyone onboard before releasing the proposal to the public, though some saw this as trying to brigade support in advance against any objections the rest of the community might have in order to discourage them.

Some community members had concerns that doubling the Sia block reward and having the Foundation sell a significant amount of Siacoins would put downward pressure on the Siacoin price, which is already very low. Others were concerned that Skynet Labs would primarily be contracted to help get the Foundation's development work started, and so the block subsidy is therefore really funding the for-profit entity Skynet Labs between that and funding Skynet Portals. There are also concerns that the Skynet Labs spinoff to focus on the profit-generating arm of Sia (Skynet) only was concealed behind the Foundation proposal, as the Skynet Labs transition was announced a day or two later.

Proposal Status

The Foundation declared the proposal to be accepted, and was expected to release a Sia hard fork on October 15, 2020 which would activate the new block subsidy to fund the Foundation around January 1, 2021. However, the fork has been delayed due to legal concerns around the technicalities of the block subsidy. The Foundation fee may need to be classed as a "donation" to the Foundation in order to achieve proper nonprofit status. Once the legalities behind the subsidy are worked out, the fork is likely to be deployed before the end of 2020.

The Sia Forums were brought back online in order to facilitate discussion of the Foundation proposal, as well as budget proposals for allocating Foundation funds. You can view the Foundation forum, these discussions, and the current status of any Foundation proceedings here.

Learn More About Sia!

This page is only an overview - we have details on all the different components of Sia!

Continue through SiaSetup by using the navigation links at the bottom of each page to learn about the different components of Sia in more detail, such as renting and hosting, Skynet, and mining Siacoins. The links are designed to walk you through the entire site to help you learn about the different Sia components in an order which makes the most sense, and which builds upon previous information from each page.

If you're here for general Sia-UI information, we have a Sia Wallet Setup Guide to help you get started with Sia-UI, as well as FAQs and troubleshooting information for the Sia-UI and Wallet (and all the other Sia components, of course!) which may be helpful for general questions and concerns.

Click Next below to continue reading!