Privacy Coins

Zcash Speeds Up With NU7: 75 Seconds Down to 25, Plus a Fee Reserve for 2031

2026-09-21

Zcash just locked in a proper network upgrade. NU7, hitting mainnet on November 5th, does two substantive things: it crushes block time from 75 seconds to 25 seconds, and it stashes 60% of transaction fees into a reserve that miners will tap starting February 2031. Both moves matter more than the headline suggests.

The speed bump first. Faster blocks mean faster shielded transactions. That's not abstract—it directly cuts the time exchanges and bridges need to wait before releasing funds. Zcash can talk privacy all it wants, but if you have to sit around waiting three times longer than on a regular blockchain just to confirm a payment, adoption hits a ceiling. Thirty seconds per block brings that closer to parity with typical payment latency expectations. The protocol doesn't sacrifice its privacy guarantees to get there.

To avoid inflating ZEC into oblivion by tripling the block production rate, the network halves the block reward and stretches the halving interval from 1.68 million blocks to 5.04 million blocks. The math works: you end up with roughly the same issuance schedule you had before. No surprise, just tighter intervals.

The meatier bit is the Network Sustainability Mechanism. Proof-of-work networks face a timing bomb. Bitcoin has subsidies forever because of its scarcity narrative. Zcash modelled itself on that promise—fixed supply, halvings, the lot. But as those subsidies dwindle, mining security depends entirely on transaction fees. That's fine when fee markets are robust, catastrophic when they're not. NU7's answer: sock away most transaction fees now, release them as supplemental miner rewards after 2031.

It's hedging against an actual structural problem. Whether it works depends on whether Zcash has meaningful transaction volume and fee depth a decade out. That's unknowable. But the mechanism at least acknowledges the problem explicitly rather than hoping it vanishes.

Community buy-in was decisive. September voting showed 99.9% support for the 25-second block time, 98.9% for preserving the halving schedule, and 96.6% backing the 2031 fee reintroduction. Those numbers came from 2.4 million ZEC voting, representing 66% of eligible participants. The five core development teams—Zcash Foundation, Project Tachyon, Valar Group, ZODL, Shielded Labs—all agreed on scope and schedule unanimously. That kind of alignment is rare in this space.

Implementation is staged. Code must be done by September 30. Testnet activation on October 6. Final go/no-go decision for mainnet on October 20, after the dev community watches the upgrade perform under realistic conditions. November 5 is still a target, not a lock.

From a pragmatic standpoint, this is exactly what privacy coin development should look like. Real technical constraint (confirmation latency hurting adoption) gets solved. Long-term sustainability risk (mining incentives) gets addressed without breaking the core promise. Users upgrading wallets will barely notice. Node operators need to handle new parameters, but nothing architectural.

Zcash is betting it can compete on both privacy and usability simultaneously. Faster blocks and deferred fees suggest the team takes that seriously enough to build the infrastructure. Whether the market gives it a chance is another question entirely.

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