Zcash launched its significant NU7 upgrade early Friday, reducing the target duration between blocks from 75 seconds down to 25 and setting up private transfers to finalize three times faster.
The network update went live at block 3,543,405, which was mined at 02:34 UTC. By 04:59 UTC, the blockchain generated an additional 225 blocks with an average spacing of roughly 39 seconds, according to data from ZecStats. Mining difficulty, which dictates the complexity of generating a block, continued to adjust toward the quicker tempo.
Zcash allows individuals to transfer funds while concealing the sender, receiver, and transferred value. Accelerated confirmations could make these transactions simpler to employ at a retail location, through a digital asset exchange, or when transferring capital across distinct blockchain networks.
A merchant can observe a transaction’s initial confirmation in approximately 25 seconds on average. An exchange demanding three confirmations could reduce its anticipated wait duration from nearly four minutes down to roughly 75 seconds.
Because each platform establishes its unique policies, the speed at which users can access their capital will likewise depend on the specific provider managing the transaction.
How it works
Maintaining synchronized operations among miners at this velocity demanded more than just adjusting the timer.
When a miner discovers a block, peer miners must receive and verify it before commencing work on the subsequent one. During this latency window, an alternative miner can generate a competing block that the network ultimately discards—and these abbreviated intervals provide less opportunity to catch up.
Zakura, a Zcash node client designed by network developers Valar Group and Project Tachyon, tested 25-second blocks across 80 computers distributed through 11 geographic regions, with each block completely filled with transactions. Under those strenuous conditions, 3.43% of mined blocks were rejected, compared to 1.57% under the previous 75-second cadence.
Its developers also minimized redundant computations. The client evaluates a transaction upon initial receipt, subsequently caching segments of that verification so it avoids repeating the process from the beginning when the transaction surfaces inside a block. Verifications relying on current account balances and historical ledger data continue to execute afresh.
Additionally, NU7 restricts the volume of private transaction data that can be packed into each block. Wallets must scan the blockchain to locate transfers intended for them, and an entity spamming the ledger with transactions can compel every wallet to perform heavier workloads.
These restrictions decrease the worst-case daily download burden from 271 megabytes to 169, as outlined in the upgrade specifications. Coupled with more frequent block creation, the specification projects that capacity for basic private payments could more than double, rising from roughly three per second to exceeding six.
Fee structures undergo modifications as well. Miners presently collect 40% of transaction fees, while the remaining 60% is removed from circulation and allocated to a reserve fund slated to subsidize forthcoming block rewards beginning in February 2031. This protocol maintains the fixed 21 million coin supply limit of Zcash.
The NU7 upgrade has officially decommissioned Sprout, the foundational 2016 privacy pool of Zcash, rendering approximately 12,224 ZEC permanently unspendable. Co-founder Sean Bowe has proposed a prospective recovery framework, though no such solution has gained formal approval as of Friday.
Read More: Zcash is about to freeze $16 million in its oldest privacy pool
Originally published at https://www.coindesk.com/tech/2026/11/06/zcash-s-landmark-nu7-upgrade-goes-live-speeding-up-private-payments.
