[xcyu]

See https://blockstack.org/blog/blockstack-whitepaper-part-1:

"Blockstack binds (human-readable) domains to public keys to establish ownership of domains. These domains have associated data records as well. These small bindings are stored on the blockchain and are tamper resistant. The actual payload from the data records is stored outside of the blockchain because blockchains have limited storage space and are not meant to be used as general-purpose databases."

[sharemywin]

How is this different than:

https://namecoin.org/

[odinho]

Blockstack project originally ran on namecoin. But it is not a secure blockchain.

Also, it stores much data in the blockchain, so it has scaling problems. Blockstack stores the zone file data in its own Atlas (DHT-inspired) network, and the zone files point to where the actual application-level data is stored.

Blockstack can work on top of any blockchain, so if Bitcoin is not the most secure anymore, it could be moved. Separating into different layers allows scaling and resiliency. And you don't have to run a blockchain, which is good, because that already exists.