Zcash’s 25-second blocks go live on public testnet ahead of schedule

Zcash has turned on its NU7 upgrade on a public test network, cutting the protocols targeted time between blocks from 75 seconds to 25. The change went live at testnet block 4,465,026 and uses valueless test coins so developers and infrastructure operators can validate software and processes without risking real ZEC. The upgrade is intended to shorten the time it takes for networks to record batches of payments, which could reduce the wait for merchants or exchanges that base actions on a fixed number of confirmations. The project notes that, if a service still requires three confirmations, the targeted wait would fall to about 75 seconds from roughly 225, though actual block intervals will vary in practice. NU7 also alters economic rules: miners will receive 40% of transaction fees while 60% will be removed from circulation and tracked in a reserve earmarked to fund future mining rewards as on-chain issuance declines. To keep the overall issuance schedule intact despite faster block cadence, the scheduled reward per block is lowered to one-third of its prior amount, so faster block production will not proportionally increase coin creation. The testnet trial is supported by both major node implementations: Zakuras implementation was released Oct. 1 and Zebras test version followed Oct. 2, and the projects earlier separate testing network has been shut down. NU7 also disables transactions from Sprout, Zcashs oldest privacy system; holders with funds in Sprout must move them before mainnet activation if they want to continue spending via the existing Sprout mechanism. Developers will review testnet findings and decide on mainnet activation on Oct. 20, with a target mainnet rollout remaining Nov. 5 but no activation block yet set.