Basically an attempt to formalize the way BitTorrent and IPFS split up files in a speccable way.
Can choose 1kb or 32kb blocks.
Data is placed in to blocks, padded, and encrypted with ChaCha.
Encrypted blocks are checksummed with Blake2b and assembled in to a tree. Higher levels of the tree just point towards the blocks inside themselves and a new hash.
Encryption key is kept as a separate part of a link. This allows pushing content to servers without the unlock key and passing the key as part of URLs out of band.