Zcash Activates NU7, Leaving 12,224 ZEC Unspendable

Zcash activated its NU7 network upgrade on November 6, changing its target block interval from 75 seconds to 25 seconds and making funds left in the legacy Sprout pool unspendable under current rules. The upgrade took effect at block 3,543,405 at about 02:34 UTC, according to blockchain tracking data. At activation, roughly 12,224 ZEC remained in Sprout, worth about $15 million to $16 million at reported market prices. NU7 rejects version 4 transactions, the format required to spend funds from the pool. The coins have not been removed from Zcash’s issued supply, but they cannot be transferred under the new rules. The upgrade specification leaves open the possibility that a future network change could restore access, either by re-enabling the transaction format or introducing another recovery method. It also warns that Sprout spending may never be re-enabled. No recovery change has been approved. Public pool balances do not identify the owners or show how much of the remaining ZEC can still be accessed with existing keys. NU7 also activates the Network Sustainability Mechanism, which directs 60% of transaction fees to a reserve and leaves 40% for miners. Reserve-backed block...