Zcash

Zcash's next network upgrade now has a date. Developer Sean Bowe proposed on 20 October activating NU7 at block 3,543,405, a height agreed at a meeting of the Zcash Improvement Proposal editors, according to CoinDesk. The proposal was merged into the specification on 21 October, and Zakura, the node software that follows and validates the chain, lists that block as the planned mainnet activation point at roughly 5 November, according to the NU7 dashboard.

The upgrade is the one that makes Zcash payments about three times faster, and it is the one that makes funds left in the chain's oldest privacy pool unspendable through normal transactions.

What changes at activation

Zcash groups transactions into blocks. NU7 cuts the target time between blocks from 75 seconds to 25. A service that waits for three confirmations before crediting a ZEC deposit would face a targeted wait of about 75 seconds instead of 225, CoinDesk reports. Actual block times vary.

Three further changes ride along. The difficulty averaging window widens from 17 blocks to 102, which the Zakura dashboard describes as steadier difficulty adjustment. Sixty percent of the fees collected in each block leave circulation and are recorded in a reserve intended to fund future mining rewards, known as the Network Sustainability Mechanism, with those payments to miners starting around February 2031, according to CoinDesk. And the scheduled reward per block falls to one-third, which preserves Zcash's existing issuance schedule rather than speeding it up, CoinDesk explains.

Sprout is going away

NU7 disables the v4 transaction format, and with it Sprout, Zcash's original shielded pool. Any coins still in a Sprout address, which begin with zc, become unspendable through normal transactions once the upgrade activates. Recovery has come up in the community forum's NU7 thread, but no mechanism exists, so it is a deadline rather than a rule change: funds need to be moved before activation, not afterwards.

The ecosystem teams agreed the timeline in that public thread, setting testnet activation for 6 October and mainnet for 5 November, with the final mainnet height chosen on 20 October, according to the NU7 timeline post.

It is worth being precise about what has not changed. New transaction formats do not appear in this upgrade, and the forum post states the changes should not affect wallets in any significant way. Infrastructure such as full nodes, indexers and block explorers may need work.

Where the rollout stands

The mainnet height is now part of the specification: ZIP pull request #1405, which sets it, was merged on 21 October. On 22 October the Zcash Foundation released Zebra 7.0.0, which supports NU7 on mainnet at height 3,543,405; its release notes say mainnet nodes must upgrade before that height to stay on the consensus chain. The upgrade ran on Zcash's test network from 6 October, activating at block 4,465,026, after Zakura released its implementation on 1 October and the Zcash Foundation a Zebra test build the following day, CoinDesk reported.

The other story: swaps against a future quantum computer

Separately, Zcash full node developer Zakura proposed a way to stop a future quantum computer from linking a user's shielded payments. The problem Adam Tucker described in a post on 18 October is structural: each shielded account has a single incoming viewing key sitting behind all of its addresses, and while a classical computer cannot recover that key from a published address, a sufficiently powerful quantum computer running Shor's algorithm could, and would then see every payment that account has ever received, Decrypt reports.

The fix targets swaps routed through NEAR Intents, where a user's shielded address is posted on NEAR's public chain. Zakura's proposal is one-time viewing keys per swap, which limits future quantum exposure to a single swap without changing spending keys and without requiring a network upgrade, Decrypt reports. Bitcoin.com points to demand for cross-chain routes into ZEC as the reason this matters now: in September, Aurora Intents processed more than $19 million across 1,718 swaps, according to Bitcoin.com.

Wallets built on Zakura's open-source libraries, including Vizor, are expected to be able to add the feature in the coming weeks, with hardware wallets to follow, according to Decrypt.

What to watch

Block 3,543,405, expected around 5 November. The date is an estimate: activation is set by block height, and the Zakura dashboard gives the date only as approximately 5 November. Node operators need software that carries the height, such as Zebra 7.0.0, before then. The immediate action item belongs to holders rather than developers, since any ZEC still sitting in a Sprout address needs to move before the upgrade goes live.