We're using blockchain technology to build a decentralized cloud where users can store data on remote hosts without having to trust them, and without giving up ownership of the data.

The blockchain is a critical part of the infrastructure because the hosts need to be paid for the services they provide, but as untrusted entities we need assurances from them. Also, if you don't have a blockchain in the middle you need something like PayPal in the middle, which is a single point of failure.