Sia is a decentralized cloud storage platform where people are able to rent out their unused disk storage to others on the network. It positions itself as a more affordable, private and secure alternative to traditional centralized cloud storage providers. The Sia blockchain serves to store the contracts formed between the host (the storage provider) and the client (the renter). The data uploaded by clients are split across multiple hosts on the network seeing to it that no single device has theShow more [+] entirety of a file. The client holds all the keys. The hosts send proof periodically to the blockchain of its continued storage until the contract expires, and is then compensated.
Siacoin (SC) is the currency used in the Sia platform and is used by renters to pay hosts. There is no limit on its total supply and it will continue to increase permanently. The first block mined was rewarded 300,000 SC and each succeeding block will decrease by 1 coin until it reaches a minimum of 30,000 SC per block.