Zcash NU7 upgrade could freeze legacy Sprout pool funds
In brief
- NU7 disables version 4 transactions, freezing access to legacy Sprout pool funds
- Sprout users must migrate ZEC before November 5 activation or lose spending ability
- Upgrade reduces Zcash block time from 75 seconds to 25 seconds
- Frozen funds would not be burned; restoration possible if community reverses change
The Sprout Migration Warning
Zcash users holding ZEC in the network's legacy Sprout shielded pool should move it before the planned NU7 upgrade or risk losing the ability to spend it. Zcash co-founder Zooko Wilcox shared the warning on X, flagging the critical deadline for affected holders.
The distinction matters. Users may hold ZEC across transparent addresses, Sprout shielded addresses, or both. Only funds in the Sprout pool face the proposed restriction. Those with ZEC solely in transparent or newer Sapling shielded addresses won't be affected.
Technical Changes and Timeline
The NU7 upgrade carries a second major change. The upgrade would also cut Zcash's target block time from 75 seconds to 25 seconds, speeding transaction confirmation across the network.
The timeline gives users a narrow window to act. NU7 is scheduled to activate on testnet October 6, with Zcash expecting to decide on October 20 whether to proceed with the targeted November 5 mainnet activation.
No Permanent Loss — Yet
The proposal includes a crucial caveat. The proposal would not burn Sprout funds and leaves open the possibility of restoring access later. If the community later reverses course, frozen funds could theoretically be recovered. For now, though, the risk is real.
At the time of writing, ZEC traded at $1,627.82, up 8% in the past 24 hours and almost 40% over the past week.
