Zcash NU7 Upgrade May Freeze Legacy Funds

Zcash users are being warned to move their funds before the upcoming NU7 upgrade or risk losing access to them. The upgrade, scheduled for November 5th, will stop accepting older transaction formats, including those used in the legacy Sprout shielded pool.

Funds left in the Sprout pool would become unspendable after the upgrade, although they won't be lost forever. Zcash Improvement Proposal-2003 states that the funds can potentially be restored later, but it's unclear if this will ever happen.

Zcash co-founder Zooko Wilcox and a user named vaspholdings on the Zcash Community Forum are urging users to check their old wallets for Sprout ZEC. Only users with funds in the Sprout pool face the risk of losing access, while those with transparent ZEC or both will be unaffected.

The NU7 upgrade also includes changes to block time and issuance, preserving the network's halving schedule. The target block time would decrease from 75 seconds to 25 seconds, and the planned changes to issuance would preserve the network's halving schedule.