In 2013, Matthew Green's team proposed the Zerocoin protocol, aiming to equip the Bitcoin network with anonymous transaction capabilities without relying on third-party intermediaries. The core idea is not complicated—breaking the transaction chain through a "burn and re-mint" mechanism, using zero-knowledge proofs to hide identities.

Three years later, in September 2016, the Poramin Insom team turned this theory into reality by launching the independent cryptocurrency Zcoin (XZC), which was once regarded as a pioneer in privacy coin technology. However, the subsequent story was less glorious—technical vulnerabilities, competition from peers, ecosystem decline, and ultimately fading away.

**Why did this happen? Simply put, two words: insecurity.**

In February 2017, the Zerocoin protocol was exploited due to a code formatting error. Attackers exploited this vulnerability to generate大量假币, causing approximately $585,000 in direct losses. But that was not the worst part.

In April 2018, the protocol was again found to have serious cryptographic flaws—attackers could destroy others' tokens and then forge new coins out of thin air. The team was forced to implement a hard fork to fix the issues, but the trust foundation was already shaky, leading to a mass exodus of developers and community members.

Later, patches like LibzerocoinV2 were released, but once labeled as "inherently insecure," it was hard to shake that reputation. Privacy coin users in the market began shifting towards more stable solutions like Monero (XMR) and Zcash (ZEC).

Comparatively, Zerocoin can only hide transaction sources; amounts and recipient addresses remain transparent. ZEC's Zerocash protocol is more thorough—encrypting both amounts and addresses. This difference reflects the rapid evolution of the privacy coin track, with subsequent solutions learning from past lessons and continuously optimizing.