Zcash NU7 Upgrade Puts Legacy Sprout Funds at Risk in November

Zcash developers have proposed block 3,543,405 for NU7 activation, expected around November 5. Funds remaining in the original Sprout shielded pool will become unspendable under the upgraded consensus rules. Older Zcash wallets are not automatically affected. The risk depends on the address type and where funds are held. NU7 also introduces faster blocks and a mechanism that defers part of miners’ transaction-fee revenue. Some Zcash holders could soon find themselves unable to move funds they still control. The network’s upcoming NU7 upgrade will eliminate the transaction format needed to spend ZEC held in Sprout, its original privacy system.