Skip to the article
Web3 Hub

Markets, protocols and policy, reported

Zcash activates NU7, cutting target block time to 25 seconds

Zcash activated NU7 at block 3,543,405, cutting target block spacing to 25 seconds and adding fee reserves that begin supporting mining rewards in 2031.

By Web3 Hub Newsroom2 min read

Zcash activates NU7, cutting target block time to 25 seconds

Zcash activated its NU7 upgrade at block 3,543,405 at 02:34 UTC on Nov. 6, cutting the target time between blocks from 75 seconds to 25, according to CoinDesk’s report. The shorter interval is intended to speed up confirmations for private payments.

How much faster should private payments confirm?

The Zcash Foundation says the target change should make the average wait for a first confirmation about three times shorter. Shortly after activation, blocks were averaging about 39 seconds as mining difficulty adjusted, CoinDesk reported.

Actual time before funds are usable still depends on network conditions and each wallet, merchant or exchange’s confirmation rules. An exchange that waits for three confirmations, for example, will take longer than a merchant accepting the first one.

What changes for shielded payments?

NU7 sets per-block limits on shielded activity to reduce the work wallets must do to find incoming payments. The Foundation says the limits more than double Orchard transaction capacity, from 2.9 to 6.6 transactions per second, while cutting worst-case sync bandwidth for light wallets by about 37%.

The upgrade also disables version 4 transactions, which Sprout, Zcash’s original shielded pool, uses. CoinDesk reported that about 12,224 ZEC remained in Sprout at activation and became unspendable.

How does NU7 change mining fees?

Under the Network Sustainability Mechanism, miners receive 40% of transaction fees while the remaining 60% goes into a reserve for future block rewards, according to the Zcash Foundation’s Zebra 7.0.0 release notes. The upgrade scales down block rewards as block times shorten, keeping the rate of new ZEC issuance essentially unchanged and preserving the 21 million supply cap.

The reserve is scheduled to begin returning to block rewards at height 8,939,664, expected in 2031. That is the next milestone in NU7’s fee mechanism.

References