India is well along with the first large public use of blockchain in the world. The three giant telcos - Bharti, Jio, and Vodafone -are cooperating to build a system designed to cover more than a billion phone users. 

Shared data will include "Soliciting entities, message aggregators, subscriber consent data and lifecycle event dates." Tanla, Tech Mahindra and IBM are providing the technology.

TRAI had ordered the companies to solve the spam problem.

This is based on reporting by Danish Khan at Economic Times. Worth a click for more information.