Zcash picks Nov. 5 for NU7: 25-second blocks, Sprout shuts

Zcash is close to locking in the date for NU7, an upgrade that makes its blocks three times faster: developers have agreed to switch it on at block 3,543,405, which should arrive around Nov. 5. Zcash developer Sean Bowe filed the proposal on Tuesday after a meeting of the ZIP editors — the group that approves changes to the protocol's rules — CoinDesk reported. On Tuesday we noted that the NU7 decision was one reason Zcash led the market rebound.

What NU7 changes

Faster blocks. The target gap between blocks drops from 75 seconds to 25. For users that mostly shows up at exchanges: a platform that waits for three confirmations before crediting a ZEC deposit would need roughly a minute and a quarter instead of close to four minutes.

Fees held back. Instead of all fees going straight to the miner who finds a block, 60% will be taken out of circulation for now. Those coins are scheduled to flow back to miners starting around February 2031. Zcash's existing schedule of halving mining rewards stays as it is.

Sprout retired. Sprout was Zcash's first shielded (private) pool, long since superseded by newer designs. NU7 disables it completely, so any ZEC still sitting in Sprout when the upgrade activates can no longer be spent. Holders have until early November to move those funds.

How the date gets locked in

Choosing a block height is only one step. As of 08:00 UTC on Wednesday, Bowe's proposal had two approvals but had not been merged into the deployment specification, which still showed the mainnet height as undecided. The public upgrade dashboard of Zakura, a Zcash node implementation, already lists block 3,543,405 as the planned activation point. Node software must ship with that height built in before the switch can happen. NU7 has been running on Zcash's testnet since early October.

Why it matters

Speed has been a practical weakness for Zcash next to newer chains, and the project has been busy elsewhere too — see its quantum-private swaps via NEAR Intents. Zcash still uses mining (proof of work); our guide to proof of work vs proof of stake explains why block times and miner incentives are tied together. Ordinary ZEC holders outside Sprout should not need to do anything, but exchanges and node operators will have to upgrade in time.