Zcash is the first blockchain system to use zero-knowledge proofs, which provide complete payment confidentiality while still being able to maintain a decentralized network using a public blockchain. Like Bitcoin, the total amount of Zcash tokens (ZEC) is also 21 million. The difference is that Zcash transactions automatically hide the sender, receiver and amount of all transactions on the blockchain. Only those who have the view key can see the contents of the transaction. Users have full control, and they can choose to provide their viewing keys to others.
ZCash is a branch of bitcoin, which retains the original mode of bitcoin and is modified based on the code of bitcoin version 0.11.2. There are two types of ZCash wallet funds: transparent funds and private funds. Transparent funds are similar to Bitcoin funds; private funds enhance privacy, transactions involving private funds are kept confidential, and transactions between transparent funds and transparent funds are publicly available. of.

1. Features of Zcash project

Compared with Bitcoin, the biggest feature of Zcash is anonymity. Transactions can automatically hide both parties and the amount of blockchain transactions, and only those who hold the key can see the specific transaction information. Of course, users can choose who has this permission.
Why is it said that Zcash can achieve true anonymity and privacy protection? Simple understanding, Zcash uses two technologies:
zk-SNARK zero-knowledge proof technology: Even if the source and flow information of the currency is completely confidential, zero-knowledge proof Technology can still verify that the user who spends money actually owns the currency.
Public blockchain: Zcash uses a public blockchain for transaction display, but it automatically hides the transaction amount, and ZEC (the token in the Zcash system) holders can observe it by viewing the key associated information.

2. Four transfer types of Zcash

Figure 1 High-level view of Zcash transfer

As shown in Figure 1, Zcash can implement four types of transfers. At present, the most common and simplest method on the Internet is the transfer between public addresses, which is no different from Bitcoin transfer. Combined with zero-knowledge proof technology, public addresses can be transferred to and from hidden addresses, and at the same time, transfers with completely hidden sending addresses and receiving addresses can also be realized.

•zk-SNARKs zero-knowledge proof
The full name of zk-SNARK is zero-knowledge Succinct Non-interactive Argument of Knowledge (non-interactive concise zero-knowledge proof). The zero-knowledge proof does not require communication between the prover (Prover) and the verifier (Verifier). In order to achieve non-interactive functions, zk-SNARKs technology needs to perform an initial trusted setup (Initial trusted setup) and set a series of public parameters to help the prover build a zero-knowledge proof to achieve completely private transfers. This series of parameters is actually used to establish a series of RSA public key encryption accumulators (RSA accumulators) in Zcash, and the corresponding parameter is the product of two large prime numbers N = p q. The parameter generator needs to destroy any records about p and q, then the system will be considered safe (this actually defaults to the assumption that the product of large prime numbers cannot be cracked). If anyone knows p or q, he will be able to easily construct a zero-knowledge proof, so as to double-spend the anonymous transfer and realize the additional issuance of currency in the anonymous system.
Therefore, these secret parameters need to be safely destroyed immediately after generating the public parameters. Zcash specially held a Parameter Generation Ceremony for this purpose, and designed a multi-party computing protocol to allow multiple independent organizations to cooperate in building parameters. Zcash’s Sapling series of public parameters Powers of Tau was generated at an altitude of 3,000 meters in early 2018 using radiation data from the Chernobyl nuclear waste. To ensure the privacy of this event. They were celebrated in a small private jet at an altitude of 3,000 feet in the US states of Illinois and Wisconsin.

·Mining structure
Unlike most PoW mining projects, Zcash allocates 10% of the token income to the team, but these tokens are not pre-mined. Instead, it will be gradually released in the first phase of mining. The specific rules are as follows:
1. One block every 2.5 minutes, and each block rewards 12.5 ZEC (so like Bitcoin, 50 mined every 10 minutes at the beginning)
2. In the first four years, 20% of the mining revenue goes into the team reward (so in the first stage miners can only get 10ZEC per block)
3. In the first month of mining, the block reward starts from 0.000625ZEC, Linear increase to 12.5ZEC (mining starts slowly)

Figure 2 Zcash mining Mine release distribution map

3. Major events of the Zcash project

ZEC will be halved for the first time at the block height of 850,000, and the reward will be reduced by 50%. After the halving, the block reward will be 6.25ZEC.

Related link:
https://baike.baidu.com/item/%E5%A4%A7%E9%9B%B6%E5%B8%81/22415313
https://z.cash/the-basics/
https://www.dprating.com/rating/report/115