While many governments have issued forms of physical, online and digital identities, these do not recognize national boundaries. Again, processing these identities in many cases will require trusted, central authorities and the data is stored centrally, which not only increases cost of data storage but also exposes that data to everyone else with access to central data centers. There is less or little control of the data on the part of the end user.
Blockchain helps in creating and management of a digital ID that is stored on a decentralized computer system. Not only can it be used for authentication purposes globally, it can be used across global platforms, and most importantly secure personal information.
Users, on their part, can share this data to any companies they wish and on their own terms.