Zcash Is About to Make Its Private Transactions Faster Than Ever

On Sunday October 28th, Zcash, a cryptocurrency network designed to enable private transactions, will deploy a system-wide upgrade called Sapling.

The upgrade will drastically improve the performance of its private, or “shielded,” transactions (reducing transaction construction time by as much as 90%).

Zcash currently allows users to choose between a lightweight “transparent” transaction or a heavier “shielded” transaction. The Sapling upgrade will make shielded transfers more efficient, moving Zcash further towards private transfers by default.

As one of the leading Zcash block explorers, we are fully prepared for the upgrade. Users needn’t worry – the block explorer will function just as it would normally.

To find out more, Block Explorer editor Ben Brown spoke to Brad Miller, head of ecosystem development at Zcash.

zcash sapling

Ben Brown: Can you briefly describe Zcash, its key features, and mission?

Brad Miller: Zcash is a privacy-protecting, digital currency built on strong science that is open source, censorship-resistant, and permissionless. 

We are creating a currency that empowers people from anywhere in the world to transact freely with whomever they choose giving them power over their money and their privacy. 

We implemented cutting-edge research in a field of cryptography known as zero-knowledge proofs performed by researchers at some of the most prestigious universities in the world to achieve these strong privacy features.

BB: From a user perspective, what will the Sapling upgrade achieve?

BM: The Sapling upgrade is our largest upgrade ever with significantly improved performance: a time reduction of 90% for constructing transactions, and a memory reduction of over 97%. 

Over time, as companies start implementing the massive efficiency improvements that Sapling enables, users will start to see shielded transactions become ubiquitous. 

The speed improvements that Sapling enables will even allow mobile phones to generate these shielded transactions, which up until this point required quite a bit of computational power only available to a laptop or desktop. 

We think this upgrade is the tipping point to move the Zcash ecosystem toward shielded transactions by default. 

zcash explained

BB: And from a technical perspective, what are you changing?

BM: This upgrade is a complete overhaul of our protocol to introduce these massive performance improvements. Instead of going into technical details I would really recommend those that are interested read our numerous blog posts on the innovations that we’ve introduced in Sapling.

BB: Do Zcash users need to do anything (e.g. migrate funds, upgrade software, change wallets etc.)?

BM: Most cryptocurrency users don’t run their own full node. My recommendations would be to confirm with your service providers for exchange services, wallets, and block explorers that they are ready for the upgrade. 

We have been working hard to make sure all service providers are prepared for the upgrade but I’m sure they would also like to hear the demand from their customers. 

If you do run a Zcash full node, upgrade your node to the latest release, v2.0.1. Users do not need to move their funds as they’re totally safe through this upgrade process.

BB: Will the upgrade result in a fork?

BM: This is a consensus change in the code so old versions of the software won’t be able to join the upgraded network. These upgrades are good for everyone in the ecosystem and there is no contention about the Sapling upgrade in general so we don’t anticipate a fork based on the older consensus rules to persist.

Further reading: What is Hard Fork in Cryptocurrency?

BB: You talk about Sapling moving you towards a “shielded ecosystem.” Can you explain what that means and why it’s so important?

BM: Zcash has two kinds of transactions. The first we call “transparent” transactions and they use an address that begins with a “t”. 

These transactions are almost identical to bitcoin in that they’re fast and efficient but they are totally public and don’t offer any privacy-preserving features. 

The second type of transaction, a “shielded” transaction, uses addresses that begin with a “z”. These shielded transactions provide strong privacy features. 

In order for the ecosystem to move away from using the transparent transactions, we had to upgrade Zcash with the kind of performance improvements that Sapling introduces. 

Now that shielded transactions will become more widespread, more individuals will have access to these private transactions therefore growing the overall private ecosystem. 

Our goal, in the long run, is for all transactions on the Zcash blockchain to be private.

BB: What is the Sapling turnstile and how does it help prevent counterfeiting?

BM: Part of the Sapling upgrade requires users to move any “shielded” funds they have from legacy Sprout addresses (the old system) to the new Sapling addresses if they wish to experience the performance improvements introduced in Sapling. 

We saw a great opportunity to audit the monetary supply of Zcash so we’ve implemented what we’re calling a turnstile in this process which prevents users from sending funds from an old Sprout address directly to a new Sapling address. 

Instead, they’ll have to move funds from a Sprout address to a transparent address, and then to a Sapling address. This process allows anyone to perform an audit of the blockchain which will make it easy to spot if any counterfeiting has been going on in the older Sprout shielded pool of funds. 

We obviously have some recommendations on how to do this to preserve privacy. Users should read more on our documentation website.

BB: Zcash was designed with scheduled breaking changes, is that correct? What type of updates did you have in mind when this was decided, and how does this compare to the upgrades made so far?

BM: We schedule older versions of our software to automatically shut down 16 weeks after release to motivate the node operators on the network to upgrade to the latest software version. 

This helps keep the node versions active on the network within a tight range and makes sure that the user experience across the network is consistent. 

Apart from that we also like to release new features regularly, we believe cryptocurrencies are still in their infancy and there are so many innovations yet to be introduced. 

We try to target a major release once every six months. This year, for instance, we released our Overwinter upgrade which made future upgrades much safer for the network and now Sapling is activating which represents the largest upgrade in our history. 

Moving technology forward and introducing improvements and features is extremely important for the growth of cryptocurrencies at this stage and we want to make sure we stay true to our core principles of quality and safety while also keeping pace with the latest cutting-edge research.

Sapling Upgrade is Fully Compatible With Block Explorer

The Sapling upgrade is due to go live on Sunday 29th October at block 419200.

Block Explorer is fully ready for the upgrade and you can continue to use the Zcash block explorer just as you would normally.

Learned something new in this article? Subscribe to the Block Explorer newsletter.

Ben Brown

Editor, Block Explorer News

Leave a Reply

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.