Zcash Sets November Launch for NU7, Its Biggest Speed Upgrade Yet

Zcash developers plan to activate NU7, the privacy-focused network's next major upgrade, on Nov. 5. The headline change is speed: the time between blocks, currently 75 seconds, will fall to 25, roughly tripling how quickly transactions get confirmed.

For a chain built on zero-knowledge proofs—cryptography that verifies a payment without exposing the sender, recipient or amount—the shorter interval means private, shielded payments could settle nearly as fast as a card transaction. Developer Sean Bowe said NU7 reaches testnet on Oct. 6, with the final mainnet activation height to be fixed on Oct. 20 once the team has observed how the network performs under the new rules.

The scope and schedule were settled by what developers described as unanimous agreement among the five organizations that build Zcash's software: the Zcash Foundation, Project Tachyon, Valar Group, ZODL and Shielded Labs. Underlying specifications are due by Sept. 30.

Paying for security without breaking the supply cap

The speedup raises a funding problem. Three times as many blocks per day would, left alone, mint three times as many new coins. NU7 addresses this through ZIP 218, which cuts the per-block reward by roughly the same factor. According to the specification, total issuance over any given stretch of real time stays unchanged.

The design preserves the halving model Zcash shares with Bitcoin: an automatic rule that halves mining rewards every few years until they approach zero, fixing the eventual total supply. Coinholders were polled on whether to retain it, and the result was emphatic—98.9% of votes cast favored keeping the model, with 2.4 million ZEC voted representing 66% of the eligible pool.

Halvings, however, steadily erode the revenue that pays miners to secure the chain. NU7's answer is a Network Sustainability Mechanism that will reserve approximately 60% of transaction fees instead of letting them vanish. Those accumulated fees begin flowing back out as supplementary mining rewards in February 2031—a date the five development teams characterized, per Decrypt, as the most conservative interpretation of the coinholder vote.

For everyday users, the practical impact is minimal. Wallets are not expected to need significant changes, and NU7 introduces no new transaction types. The stakes are longer-term: whether Zcash can continue compensating miners decades from now while honoring the fixed-supply commitment that attracted Bitcoin-style holders.

The upgrade arrives after a turbulent stretch for the network's software and an exceptional one for its price. In July, Zcash deployed Ironwood, an upgrade that patched a four-year-old vulnerability which could have enabled counterfeiting of ZEC—a scare that briefly sent the token down 38%.

The coin has since rebounded decisively. ZEC is up more than 2,500% over the past year, a run supported by the Ironwood fix and by Grayscale's launch of a spot ETF, an exchange-traded fund that tracks the coin's price and gives investors exposure without requiring them to hold ZEC directly.