What Is Zcash and How Does This Privacy-Focused Cryptocurrency Work?

What Is Zcash?

Zcash is a public, decentralized cryptocurrency with its own token: ZEC. What makes Zcash special is that you can choose how you send ZEC. You can make a transparent payment, where important details are public, or a shielded payment, where those details stay much more hidden.

Zcash runs on a public blockchain. That means transactions on the network are recorded and checked by participants. With transparent transactions, this looks a lot like Bitcoin: addresses and amounts are visible on the blockchain.

With shielded transactions, it works differently. Zcash uses zero-knowledge proofs for this, specifically zk-SNARKs. These are cryptographic proofs that let you show a payment is valid without immediately giving away sensitive details. Think of the amount, the sender address, and the recipient address.

That freedom of choice matters. So Zcash is not automatically fully private with every payment. Privacy depends on the type of transaction you use, your crypto wallet, and how you move your ZEC.

The maximum supply is 21 million ZEC, just like Bitcoin. One ZEC can be divided into 100 million smaller units called zatoshi.

Key Takeaways

• Zcash is a public blockchain and cryptocurrency with ZEC as its native token.
• You can send ZEC transparently or in a shielded way.
• Shielded payments use zk-SNARKs to keep data hidden.
• Transparent payments make addresses and amounts publicly visible.
• There can be a maximum of 21 million ZEC.

How Does Zcash Work?

Zcash works because transactions are recorded on a public blockchain and checked according to fixed rules. The network always verifies whether a payment is valid and whether the same ZEC is not being spent twice.

With a transparent payment, this is pretty easy to follow. The addresses and amounts are visible on the blockchain. With a shielded payment, nodes, the computers that verify the network, still need to be able to confirm that everything is correct. They just do not get to see the sensitive payment details.

So how does that work? The sender creates a zk-SNARK, a kind of mathematical proof. With it, the sender proves, for example, that they are allowed to spend enough ZEC and are following the rules. The proof does not publicly show which shielded address the payment came from, which address the money is going to, or how much ZEC is being sent.

Shielded amounts are recorded as cryptographic commitments. You can think of a commitment as a sealed digital record of value: the network can use it for calculations and verification, but it cannot just see what amount is inside.

When that value is spent later, a nullifier appears. This is a unique marker that can only be valid once. If the network sees the same nullifier again, it knows someone is trying to spend the same shielded value a second time. That is how Zcash prevents double spending.

Zcash has multiple generations of shielded technology. Since Network Upgrade 5 in May 2022, there is also Orchard. Orchard uses Halo 2 and does not need a trusted setup. A trusted setup is an earlier step where special cryptographic parameters are created. Older systems, Sprout and Sapling, did use those parameters through ceremonies with multiple participants.

In short: Zcash tries to do two things at once. Payments need to stay verifiable, but the sensitive details do not have to be on the blockchain for everyone to see.

How Does Zcash Protect Transaction Privacy?

With a fully shielded payment, Zcash can hide the sender address, recipient address, amount, and any memo from the public. A memo is an extra message you can add to such a payment, and it travels along encrypted.

The zk-SNARK proves that the payment is valid without publicly showing which earlier shielded payment is being spent. That lets the network enforce the rules without exposing all payment information openly.

Example: Suppose you send ZEC to someone through a fully shielded payment. The blockchain will still show that a transaction exists and that a fee was paid. But publicly, the amount and the shielded addresses involved are not readable.

Zcash also has viewing keys. With one of these keys, you can give someone read access to relevant transaction data without letting that person spend your ZEC. That can be useful if you want to share access voluntarily for things like bookkeeping, an audit, or tax reporting.

One important thing to know: privacy does not mean a transaction is completely invisible. The transaction itself is still on the public blockchain, and the fee is visible. Zcash also does not hide your IP address by default. Someone watching network traffic may be able to connect timing and other network metadata to transactions.

Your own behavior matters too. If you move amounts through the transparent side, share information, or create recognizable patterns, that can reduce privacy.

What Is the Difference Between Transparent and Shielded Transactions?

The biggest difference is which data is publicly visible. Transparent transactions are like regular Bitcoin transactions: addresses and amounts on the transparent side are visible to everyone on the blockchain.

A fully shielded payment goes from a shielded address to another shielded address. In that case, the sender address, recipient address, amount, and an optional memo are not publicly readable.

You can also move ZEC from the transparent side into the shielded part. This is called shielding. In that case, the transparent input and the amount leaving that visible side are public.

The reverse step is called deshielding: you move ZEC from the shielded part to the transparent side. Then the transparent output and the amount arriving there are visible.

So shielded does not mean a magic switch that erases all traces from an entire payment history. When moving between the two parts, amounts and timing on the transparent side remain visible. Also, the existence of the transaction and the fee stay publicly observable.

What Is Zcash Used For?

Zcash is used to store, receive, and send ZEC directly to others. You can do that through a crypto wallet that supports Zcash.

One possible use is a payment where you do not want the amount and the addresses involved to appear publicly on the blockchain. For that, both your crypto wallet and the payment route need to support shielded transactions. That is not a given with every service.

The encrypted memo can also be useful. You can use it to send extra information with a shielded payment without making that memo publicly readable.

If you want to give someone voluntary access, you can use a viewing key. Someone with that key can view relevant shielded transaction data, but does not automatically get the ability to spend your ZEC.

Technically, you can use ZEC for payments to individuals, service providers, stores, or donations. In practice, acceptance varies by region, merchant, wallet, and payment service. A payment through a crypto exchange or another custodial service is not automatically shielded either. So check ahead of time which transaction types are actually supported.

What Is the Difference Between Zcash and Bitcoin?

Zcash builds on a Bitcoin-like way of paying, but adds shielded transactions with zero-knowledge proofs. Bitcoin and Zcash both use a public blockchain, but Zcash offers not only transparent payments but also a built-in option to shield sensitive payment data.

Bitcoin transactions use publicly traceable UTXOs. You can think of a UTXO as a piece of unspent bitcoin value that you use as input for a new payment. Zcash also has shielded notes: shielded pieces of value that are checked with commitments and nullifiers.

Zcash was created in 2016 from Bitcoin open-source code, with extra cryptography for shielded transactions. At the protocol level, Bitcoin does not offer the same zk-SNARK-based shielding of sender, recipient, and amount.

There are also similarities. Under their rules, both protocols have a maximum supply of 21 million coins. That does not mean the technology, use, or risks are the same.

Zcash also has features that Bitcoin does not have in the same way at the protocol level, such as encrypted memos and viewing keys. Bitcoin addresses are pseudonyms, by the way: they do not automatically show a real name, but confirmed transactions and amounts are publicly visible.

What Are the Benefits of Zcash?

Zcash’s main benefit is that it can offer strong on-chain confidentiality with fully shielded payments. Public observers then do not automatically see who is paying, who is receiving, what amount is being sent, or which memo was included.

Other benefits include:

• Verification without showing all details: zk-SNARKs let the network check whether a payment is valid without publishing sensitive payment data.
• Choice: you can choose between transparent and shielded transactions, depending on your goal and your wallet’s support.
• Selective access: with viewing keys, you can let someone view relevant data without giving away your ability to spend.
• Encrypted memos: you can send extra information with a shielded payment.
• Fixed maximum supply: the protocol sets a limit of 21 million ZEC.

These benefits are mostly technical. They do not guarantee that every payment stays private in practice. How good your privacy is also depends on your wallet behavior, visible transitions, and network metadata.

What Are the Downsides of Zcash?

Zcash also has clear limitations. Privacy is optional, so a transparent transaction does not hide addresses and amounts on the transparent side at all.

The transition between transparent and shielded can also reveal information. With shielding and deshielding, visible amounts and timing may be linkable. If you use recognizable patterns, that can reduce your privacy.

Historical analyses of Zcash transactions showed that recognizable use can shrink the anonymity set. The anonymity set is simply the group of possible transactions or users within which you are harder to distinguish. That does not mean every current shielded payment is traceable, but it does mean privacy requires careful use.

Another thing to watch: Zcash does not hide your IP address by default. A network observer may be able to connect IP data and transaction metadata. So shielded payment data alone does not automatically solve that.

Also, not every crypto wallet, crypto exchange, or payment service supports shielded transactions. You need to check in advance whether you can actually receive, store, and send ZEC in a shielded way through the service you want to use.

Finally, the technology is fairly complex. Zcash has multiple generations of shielded protocols. Older systems used a trusted setup, while Orchard with Halo 2 removes that requirement for Orchard. Those different techniques make the protocol harder to understand than a fully transparent payment system.

Conclusion

Zcash is a cryptocurrency that gives you the choice between transparent and shielded payments. The ZEC token runs on a public blockchain, but zk-SNARKs make it possible to prove a valid payment without publicly showing the sender, recipient, and amount in fully shielded transactions.

That makes Zcash interesting for people who want more privacy in payments, but that privacy does not happen automatically. Transparent transactions remain visible, transitions between the two parts can reveal information, and network metadata can also give things away. So always check whether your crypto wallet or payment route supports shielded transactions, and keep in mind what you make visible yourself.