Blockchain is a shared, virtual ledger that can record the history of transactions that cannot be altered. Each transaction is put into a block, and those blocks are linked in an irreversible chain. The record is distributed among all users, making access and the ability to reconcile records faster; Each member of the network has access rights so that confidential information is shared on a need-to-know basis. The process makes transactions secure, faster and more transparent. Tools in this subcategory use Blockchain to enable advertising tools.