Zcash Launches NU7 Upgrade on Testnet to Cut Block Times

The reduction in block intervals is designed to accelerate confirmation times, allowing the network to produce roughly three blocks in the time it currently takes to generate one. Beyond timing adjustments, NU7 introduces a Network Sustainability Mechanism, which redirects a portion of transaction fees into a reserve pool to support future block rewards. To maintain stability during this transition, the upgrade implements new limits on shielded actions, an effort intended to shield wallets from potential spam as block production frequency increases.

Developers are closely monitoring the network performance ahead of a final decision scheduled for October 20. This review will determine if the protocol is ready for a full mainnet rollout, currently targeted for November 5. A significant shift accompanies this upgrade: once the changes reach the mainnet, version 4 transactions will be disabled. This move renders ZEC held in the legacy Sprout shielded pool unspendable, forcing holders to migrate their assets before the activation height takes effect. The upgrade follows the recent Ironwood deployment, continuing Zcash's ongoing efforts to refine its consensus rules and long-term sustainability.