Zcash's Coming Hard Fork Could Pave the Way for More

Zcash's first hard fork is coming up, and devs expect it to activate without a hitch, preparing zcash for bigger, better upgrades in the future.

AccessTimeIconMar 22, 2018 at 8:00 a.m. UTC
Updated Sep 13, 2021 at 7:43 a.m. UTC
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Privacy-focused cryptocurrency zcash is gearing up for its first hard fork.

And while that may call to mind bitter debates over development or excitement about free coins, actually zcash's first hard fork – dubbed "Overwinter" – isn't about either. Instead, the cryptocurrency's developer team is hoping to lay the groundwork for more dramatic upgrades in the future.

While there are some features being added to zcash in the update, Zooko Wilcox, co-founder and CEO of Zerocoin Electric Coin Company, which develops the network, told CoinDesk, "The purpose of this is to get practice doing network upgrades."

As such, the developer team has been carefully informing the zcash community about the process so "they know how to do this regularly from now on," he continued.

Most of Zcash's developer energy is focused on perfecting Overwinter, which is slated for June, while also looking ahead to zcash's next hard fork upgrade, called Sapling. This subsequent hard fork will usher in a big change, speeding up transactions on the network while maintaining the same level of privacy the cryptocurrency already provides.

Speaking to the names of the upgrades (zcash's software stage is currently called "Sprout"), Wilcox said he foresees a smooth transition.

He told CoinDesk:

"If you have a sprout, after it has endured cold, it becomes tougher."

And should zcash survive this winter, surely, according to its devs, the cryptocurrency will be stronger.

While the thinking on forks has shifted some, hard forks have been seen as controversial since they are a kind of governance mechanism that forces users to move along with a technical change. Should the zcash community ride out this first transition, though, zcash developers believe it can handle others.

"If I say 'hard fork,' immediately people ask me what the name of the new coin is and if there will be an airdrop," Wilcox said, adding that he prefers to call Overwinter a "network upgrade."

But according to Wilcox, that won't be the case with this hard fork, since "people would rather have version 2.0" of zcash with new features that unlock immediately.

Through the winter

First and foremost, Overwinter adds so-called replay protection to zcash, whereby should some users stay on the old chain and send transactions, those transactions will not be repeated on the new chain.

According to Wilcox, this is more of a precaution instead of a feature, since he doesn't expect any users to not upgrade to the new system (albeit, this could be a problem with future hard forks that introduce more controversial upgrades).

The feature that Wilcox is most excited about, then, is the addition of "transaction expiry," a mechanism which prompts transactions to expire after an hour.

While this might sound odd, it quite frequently happens that transactions get stuck, held in limbo because users don't pay high enough fees to make miners pick up the transaction and add it to a block.

"Some people think it's a bad idea," Wilcox said.

Those in opposition believe it could lead to security issues, but to Wilcox, this feature will prevent users from losing money if they accidentally send a transaction on the wrong chain.

As such, this feature allows zcash, which was derived from bitcoin's code, to further differentiate itself from the largest cryptocurrency by market capitalization.

The other big change that Overwinter will bring to the zcash network will address "signature verification performance," and this too will further move zcash into a new role, not defined by bitcoin.

According to Wilcox, "We have a bug we inherited from the bitcoin codebase where if you verify signatures with a whole lot of [unspent transaction outputs or UTXOs], it takes too long. This fixes that."

The holy grail?

Beyond these known upcoming hard forks, zcash has other plans for tackling one of cryptocurrencies most notorious challenges – scaling.

Sure enough, zcash has already proven to be the cryptocurrency of wild ideas, with its second cryptographic ceremony for keeping the system private taking place recently. (Participants in such events are known to take bizarre measures, including using strangers answers to questions to acquire randomness and putting a flamethrower to a computer.)

While the zcash developer team hasn't been very public about their more experimental research so far, Wilcox gave CoinDesk some insight into their work.

For instance, the team is following all the big ideas in the crypto space today, including ethereum's plasma and sharding work and bitcoin's open-source Lightning Network development.

That said, Wilcox isn't sure who will find the scaling holy grail first.

"Maybe it'll be us," he said, going on to argue zcash might be able to gain scalability by focusing on its own specialty – zk-snarks.

Known as the technology anonymizing zcash transactions, zk-snarks are also a promising avenue for compressing blockchain data.

But he isn't trumpeting the solution just yet, arguing that even if it does work, it will take "years" for the benefits to trickle down to users.

Still, Wilcox concluded that zcash is in the race:

"We're researching to see if using zk-proofs can make a fully scalable blockchain."

Zcash image via Shutterstock


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