Sia is a decentralized storage platform marketplace, where users can rent out their unused hard drive storage space.


Sia aims to make cloud storage faster, cheaper and more secure by democratizing cloud storage services. Smart contracts split apart, encrypt and distribute files across the nodes of the decentralized network with no possibility for a third party to interfere. Sia expects to achieve reliability by cryptographic proofs of storage as well as erasure coding (via Reed-Solomon codes). Erasure coding allows a file to be split into many pieces, such that the original file can be recovered using only a few of the files, meaning that if a certain number of the storage nodes go offline, the files can still be recovered. Sia is mainly written in Go.

Payments on the platform are made in Siacoin: out of each payment a fee is subtracted, which is paid out to the holders of Siafund, the second cryptocurrency of the platform, which consist of 10,000 completely premined tokens. Since Sia’s parent company holds the vast majority of Siafunds, this method eventually facilitates ongoing funding for the development of the platform. Sia was created by Nebulous Labs, lead by David Vorick and Luke Champine. The idea was originally conceived at HackMIT 2013. The network officially launched in June 2015.