Zcash Activates 25-Second Blocks on Public Testnet Ahead of Schedule

Zcash has activated its NU7 upgrade on the public testnet, reducing the target time between transaction blocks from 75 seconds to 25 seconds. The test gives exchanges, wallets and developers an opportunity to evaluate the changes ahead of a planned November mainnet rollout.

NU7 went live at block 4,465,026. Zakura, software used to track Zcash and validate its transactions, now shows the updated rules as active on the public testnet. A separate earlier testing network has been taken offline.

Each block contains a batch of transactions, so producing blocks more frequently could reduce the time merchants wait to accept payments or exchanges take to credit deposits. For example, a service requiring three confirmations would face a targeted wait of roughly 75 seconds instead of 225 seconds if its confirmation policy remained unchanged. Actual block production times can differ from the target.

The public testnet uses coins with no monetary value, allowing developers and infrastructure providers to test the upgrade without putting real ZEC at risk.

Both major Zcash node implementations support the test. Zakura released its updated software on Oct. 1, followed by a test version of the Zcash Foundation’s Zebra client on Oct. 2. Operators must run compatible software to participate in the upgraded network.

NU7 Changes Zcash Mining Rewards

The upgrade also modifies the distribution of transaction fees. Miners will receive 40%, while the remaining 60% will be removed from circulation and assigned to a reserve designed to support future mining rewards. These rewards compensate miners for processing transactions as new ZEC issuance gradually declines.

Despite the move to faster blocks, Zcash will not create three times as many new coins. The scheduled reward per block will fall to one-third, keeping the broader issuance schedule intact.

NU7 also disables transactions associated with Sprout, Zcash’s oldest private-payment system. Users holding funds in Sprout would need to transfer them before the upgrade reaches mainnet if they want to preserve the ability to spend those funds through the existing system.

Developers are scheduled to review the public testnet results and make a decision on mainnet activation on Oct. 20. Nov. 5 remains the target date for the rollout, although no specific mainnet activation block has been established yet.