In the late 1990s, Matthew Green @matthew_d_green, then a computer science student, posed a critical question:
If encryption can't truly solve the privacy problem, is it really protection?

In 2013, he teamed up with Eli Ben-Sasson, Ian Miers, and others to propose the Zerocash protocol.
Built on zk-SNARKs (Zero-Knowledge Succinct Non-Interactive Arguments of Knowledge), this protocol allowed for fully private, on-chain transactions without revealing transaction details, opening a new path for digital privacy.