Decentralized Storage

The Libri API exposes simple Put / Get endpoints and a streaming Subscribe endpoint for storage notifications across the entire network.
InterPlanetary File System (“IPFS”) [ipfs] uses much of the same design as BitTorrent—peer-to-peer file sharing, possible caching of popular documents, tit-for-tat incentive accounting—but it addresses the stored data by a hash of its content instead of a filename.
This content-addressing combined with a simple link structure allows it to behave as a Merkle DAG, giving it great flexibility in being able to store and model many forms of data, from simple blobs to files to whole filesystems.
At its heart, though, IPFS looks very much like BitTorrent: peers host data that others may optionally copy and host as well, and the addresses of the peers hosting each object are stored in a Kademlia DHT.
Peers in the Libri network are called Librarians, and clients of these peers are called Authors. Librarian peers never see the plaintext content of a document and deal only with encrypted chunks of one.
Author clients convert a plaintext document into these encrypted chunks and back again.

The Sia software divides files into 30 segments before uploading, each targeted for distribution to hosts across the world.
File segments are created using a technology called Reed-Solomon erasure coding, commonly used in CDs and DVDs. Erasure coding allows Sia to divide files in a redundant manner, where any 10 of 30 segments can fully recover a user's files.
This means that if 20 out of 30 hosts go offline, a Sia user is still able to download her files.
Threefish encryption algorithm.
Merkle construction phase requires heavy preprocessing. Logarithmic of the file size.

References