Zcash activates NU7 upgrade, cutting block times to 25 seconds and freezing Sprout pool
Zcash has activated its NU7 mainnet upgrade, reducing target block times from 75 seconds to 25 seconds, redirecting 60% of transaction fees into a future reserve, and leaving approximately $16 million in its legacy Sprout privacy pool unspendable.
Zcash activated its landmark Network Upgrade 7 (NU7) on mainnet at block 3,543,405, mined at 9:34 p.m. ET Thursday, according to on-chain data reported by Unchained. The upgrade cuts Zcash's target block time from 75 seconds to 25 seconds, speeding up private payments and reducing the wait time for three confirmations from four minutes to 75 seconds. To maintain consistent daily issuance under the threefold speed increase, individual block rewards were divided by three.[5][6][9][15][17][18]
A central feature of NU7 is Shielded Labs' Network Sustainability Mechanism, governed by ZIP 235 and ZIP 237. The protocol removes 60% of transaction fees from circulation while leaving miners with the remaining 40%. The reserved fees will eventually be reissued alongside regular block rewards starting at block 8,939,664 in 2031, all while preserving Zcash's 21 million ZEC supply cap and halving schedule.[1][3][4][7][11][18]
The hard fork also dropped support for version 4 transactions, permanently freezing coins remaining in Sprout, Zcash's original privacy pool launched in 2016. At the time of activation, about 12,224 ZEC, worth roughly $16 million, remained stranded in the Sprout pool without an available transaction format to withdraw or spend them.[2][8][10][12][13][16][17][18]
Key facts
- Zcash activated the NU7 network upgrade at block 3,543,405 at 9:34 p.m. ET Thursday.
- The upgrade lowered the target block interval from 75 seconds to 25 seconds, dividing block rewards by three to keep total daily issuance unchanged.
- The Network Sustainability Mechanism takes 60% of transaction fees out of circulation, leaving 40% for miners.
- Removed fee revenue will be reissued through block rewards starting at block 8,939,664 in 2031, keeping Zcash within its 21 million coin cap.
- NU7 dropped support for version 4 transactions, leaving approximately 12,224 ZEC worth about $16 million frozen in the legacy Sprout pool.
Sources · 16 sources
- DE
DecryptArticle ·
Zcash's NU7 Upgrade Goes Live, Recycling 60% of Fees to Fund Future Block Rewards The Network Sustainability Mechanism will reissue removed ZEC from 2031 within the 21 million cap, as the community debates its dev fund.
Open source - CO
CoindeskArticle ·
Zcash is about to freeze $16 million in its oldest privacy pool About 12,200 ZEC remains in Sprout, the privacy pool Zcash launched in 2016. Roughly 10,000 coins have left over the past week, but only about 40 moved out Wednesday.
Open source - CO
Cointelegraph@CointelegraphPost on X ·
🔥 TODAY: Zcash has activated its NU7 upgrade on mainnet, bringing the Network Sustainability Mechanism. The new mechanism pulls 60% of transaction fees from circulation for later reissue through future block rewards. https://t.co/xTqOsRIeOq
Open source - CB
Crypto Banter@crypto_banterPost on X ·
🚨ZCASH NU7 ACTIVATES ON MAINNET! @Zcash announced the network upgrade is live, cutting target block times from 75 seconds to 25 seconds. The upgrade also takes 60% of transaction fees out of circulation under the Network Sustainability Mechanism, reducing immediate zcash:native supply while speeding up private payments.
Open source - TB
The Block@TheBlockCoPost on X ·
THE BLOCK: Zcash announced that NU7 has activated on the mainnet. The upgrade cuts the target block time to 25 seconds from 75 seconds. zcash:native https://t.co/cc8ZOAxooK
Open source - ME
mert@mertPost on X ·
big with the recent upgrade, zcash is now 3x faster! trillions https://t.co/JC8gRx7qhw
Open source - TB
The BlockArticle ·
Zcash’s major network upgrade NU7 goes live on mainnet, cutting block time by threefold NU7 also activates the Network Sustainability Mechanism, which removes 60% of each block's transaction fees from circulation.
Open source - DE
Decrypt@DecryptMediaPost on X ·
Zcash Upgrade Could Lock $16 Million in Crypto Forever https://t.co/bAmK0NquKO
Open source - CO
CoindeskArticle ·
Zcash’s landmark NU7 upgrade goes live, speeding up private payments NU7 cuts the target time between blocks to 25 seconds, reduces the work wallets must do to find private payments and sets aside fees for future miners.
Open source - CB
Crypto BriefingArticle ·
Zcash to freeze $16M in its oldest privacy pool with NU7 upgrade The NU7 upgrade may lead to a liquidity squeeze and impact investor sentiment if significant ZEC remains frozen in the Sprout pool. The post Zcash to freeze $16M in its oldest privacy pool with NU7 upgrade appeared first on Crypto Briefing .
Open source - CN
crypto.news@cryptodotnewsPost on X ·
JUST IN: Zcash has activated the NU7 upgrade, introducing a new sustainability mechanism The upgrade directs 60% of transaction fees into a reserve for potential reissuance through future block rewards. https://t.co/NJHizyPKfd
Open source - CP
Crypto Patel@CryptoPatelPost on X ·
$16M IN $ZEC COULD BECOME INACCESSIBLE! Zcash is retiring its oldest privacy pool, Sprout, through the NU7 upgrade. Around 12,226 ZEC remain, which could become unspendable once legacy transactions are disabled. ➡️ Short-term: Negative for user confidence and ZEC sentiment. ➡️ Long-term: Potentially positive for network security and modernization. My take: Good for technology, but concerning for decentralisation. Can a blockchain make user funds inaccessible in the name of security?
Open source - CT
Coin TelegraphArticle ·
Zcash NU7 upgrade goes live, leaves 12,224 ZEC stranded in Sprout pool Zcash’s NU7 upgrade has rendered about $15 million in legacy Sprout funds unspendable, although a future network upgrade could potentially restore access.
Open source - AI
Analytics Insight@analyticsinmePost on X ·
𝗭𝗰𝗮𝘀𝗵 𝗣𝗿𝗶𝗰𝗲 𝗛𝗼𝗹𝗱𝘀 𝗔𝗯𝗼𝘃𝗲 𝗨𝗦𝗗 𝟭,𝟯𝟬𝟬 𝗮𝘀 𝗡𝗨𝟳 𝗨𝗽𝗴𝗿𝗮𝗱𝗲 𝗙𝘂𝗲𝗹𝘀 𝗕𝗿𝗲𝗮𝗸𝗼𝘂𝘁 𝗧𝗮𝗹𝗸𝘀 Zcash Price Holds Above USD 1,300 as NU7 Upgrade Goes Live, With Bulls Eyeing a Breakout Above USD 1,340! Zcash (ZEC) gained approximately 2% to trade near USD 1,308, showing resilience despite a broader cryptocurrency market sell-off and rising volatility. The highly anticipated Network Upgrade 7 (NU7) officially activated on November 6, reducing block confirmation targets from 75 seconds to just 25 seconds, potentially making Zcash payments three times faster. Meanwhile, the NU7 upgrade introduced a new fee distribution mechanism, allocating 40% of transaction fees to miners and reserving 60% for future rewards. Will ZEC break above USD 1,340 and rally toward USD 1,698, or could ETF withdrawals trigger another correction? #Zcash #ZcashPrice #ZECPricePrediction #ZcashNU7 #Cryptocurrency #PrivacyCoins #ZcashUpgrade #ZECETF #Altcoins #AnalyticsInsight #AnalyticsInsightMagazine Read More 👇 https://t.co/bHLZmuuncK
Open source - BS
BSCN@BSCNewsPost on X ·
Zcash Just Got 3x Faster Without Giving Up Privacy NU7 update for @Zcash is now available. The block time has been reduced from 75 seconds to 25 seconds, making transactions almost three times faster. Privacy capabilities remain intact. The waiting period for three confirmations is reduced from four minutes to 75 seconds. $ZEC issuance stays the same but will be rebalanced. New restrictions are implemented on shielded interactions to limit potential spam attacks, and 60 percent of all fees will be locked in a miner reserve starting in 2031. This update will affect exchanges, wallets, and merchant services that depend on confirmations.
Open source - DE
DecryptArticle ·
Zcash Upgrade Could Lock $16 Million in Crypto Forever Zcash's latest upgrade promises faster transactions, but thousands of coins remain in an aging privacy system that will soon stop accepting withdrawals, potentially leaving their owners empty-handed.
Open source - LS
Laura Shin@laurashinPost on X ·
Zcash's NU7 upgrade went live at block 3,543,405 at 9:34 p.m. ET Thursday, moving the network to 25-second blocks. About 12,224 ZEC, roughly $16 million, in the old Sprout pool can no longer be spent. https://t.co/nDTtRnfS1g
Open source - UN
UnchainedArticle ·
Zcash Activates NU7, Taking 60% of Transaction Fees Out of Circulation Zcash’s NU7 network upgrade activated on Thursday night, switching on the Network Sustainability Mechanism (NSM) , a fee-recycling system that pulls ZEC out of circulation now and reissues it through block rewards years from now. Shielded Labs’ Jason McGee had announced it in an X Article that afternoon. McGee had written that the NSM “will activate later today as part of NU7,” and described it as Shielded Labs’ first major mainnet deployment. Block 3,543,405 , the activation height set in the ZIP 259 deployment spec , was mined at 9:34 p.m. ET, according to Blockchair . Get Unchained’s crypto news in your inbox with the free Unchained Daily newsletter . What the NSM Changes ZIP 259 sets reissuance to start at block 8,939,664. By Unchained’s count, that is about 5.4 million blocks after activation, which at NU7’s new block time lands in early 2031. McGee wrote that “reissuance will begin in 2031.” Zcash’s 21 million ZEC cap and its halvings stay as they are. Under ZIP 235, the miner keeps 40% of each block’s fees and the other 60% leaves circulation; ZIP 237 then pays that ZEC back out gradually, on top of regular block rewards. Shielded Labs’ first design “would have replaced halvings with a smooth issuance curve,” McGee wrote, but coinholders did not back it, though community panels did. A version that keeps halvings won broad support, he wrote. Coinholders voted in September for 25-second blocks and existing halvings. “We still think the original design was simpler and better, but we respect the process that led us here,” he wrote. Faster Blocks, No More Sprout NU7 also cuts the block target from 75 seconds to 25 seconds , with block rewards divided by three so daily issuance is unchanged, the Zcash Foundation said in its Zebra 7.0.0 release notes . It also sets per-block limits on shielded activity and drops support for version 4 transactions. Sprout transfers have no other format, so coins still in the Sprout pool can no longer be spent. About 12,224 ZEC , worth roughly $16 million , sat in the Sprout pool at the activation block, according to Blockchair’s block data . NU7 went live on Zcash’s testnet in early October. The Zcash Foundation shipped Zebra 7.0.0 on Oct. 22 as its first stable Zebra release able to run NU7 on mainnet. “All Mainnet node operators must upgrade before NU7 activates to stay on the consensus chain,” it had warned. The 50,000 ZEC Proposal McGee also pointed to a separate proposal that “would require Zcash Community Grants (ZCG) to contribute 50,000 ZEC from its treasury to the NSM.” That draft ZIP, which would also end ZCG’s 8% funding stream and route it to a new development and legal-defense lockbox until the third halving, was still an open, unmerged pull request on GitHub on Thursday. McGee co-wrote it with Zooko Wilcox and Sean Bowe, and the three put it forward in late October . ZCG dropped its own funding cut earlier this week. ZEC traded near $1,313 on Thursday evening, roughly flat over 24 hours, according to Blockchair data . Related Listen: Bits + Bips: How Claude Found Zcash’s Counterfeiting Bug The post Zcash Activates NU7, Taking 60% of Transaction Fees Out of Circulation appeared first on Unchained .
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