Published on Mar 31, 2018

Zcoin is the first full implementation of the Zerocoin Protocol, which allows users to have complete privacy via Zero-Knowledge cryptographic proofs. It is worth noting that Zcoin is unrelated to other cryptocurrencies utilizing the Zerocash Protocol. Although Zerocash is a development from Zerocoin, their respective implementations are not simple forks of each other, but rely on different cryptographic assumptions with various tradeoffs. Both approaches supplement each other quite nicely, and a good way to describe them would be sibling projects.

The Zerocoin Protocol is being actively researched and improved, such as by a new extension that when implemented would hide transactions and address balances.

A common misconception is that Zcoin is a fork of Zcash. Zcoin is based off the Zerocoin paper while Zcash is based off the Zerocash paper. While the Zerocoin paper and Zerocash paper share common authors and both use zero knowledge proofs, they rely on different cryptography. There is otherwise no relation between the two projects.

Zcoin uses RSA accumulators which were introduced in 1993 as the foundation of our anonymity scheme while Zcash uses zk-SNARKs which was recently formulated in 2014 and very few ppl understand it. Comparatively, RSA cryptography is one of the earliest form of public key cryptography which was publicly described in 1977, has been battle tested and forms the basis of many encryption schemes in wide use today such as HTTPS, SSH logins and PGP for e-mail. It also uses the Fiat-Shamir transform scheme that was published in 1986.

Peter Todd’s blog post illustrates this perfectly in pointing out that if RSA breaks, Zcoin would probably be the least of your concerns.

zk-SNARKs as used in Zcash requires on more novel cryptographic assumptions which have not been really been put under serious scrutiny.

It is a serious enough problem that the Zcash devs themselves are trying to find alternatives to it in the form of zk-STARKs which remain in research stage and are currently impractical to use. If these cryptographic assumptions do not hold, then the cryptography in Zcash breaks. This combined with an unauditable supply that may make it impossible to detect such problems means that zk-SNARKs although technologically advanced, is taking certain risks to achieve it.

You can buy Zcoin (XZC) at the following exchanges.

Bittrex

Bitcoin.co.id (IDR pairing)

Binance

CoinExchange.io

Bitsquare

BX Thailand (THB pairing)

Cryptopia

LiteBit.eu

Nova Exchange

UPBit.com

AEX.com

There will be 21.4 million Zcoins. Zcoin follows the same halving cycle as Bitcoin (every 4 years).

It was originally planned that 20% of Zcoins (10 XZC per block) in the first 4 years will be distributed to the Founders’ Reward which is equivalent to 10% of total supply. The Founders’ Reward consists of Poramin Insom (lead dev and Founder) (4%), seed investors (12%) and the team wallet (4%).

However upon the launch of Znodes, the Founders and the team have agreed to reduce this to 14% of the block reward: 2% Poramin Insom, seed investors (6%) and team wallet (6%).

To find out how the Founder’s Rewards are used, see here.

After the first 4 years, the block reward goes completely towards the miners and Znode rewards.