Zcash activates NU7, sets 25-second blocks, sends 60% of fees to reserve

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Zcash activated NU7 at mainnet block 3,543,405. The upgrade reduces target block spacing from 75 to 25 seconds, recalibrates per-block rewards to preserve the issuance path, introduces a fee-reserve mechanism for future security, and requires NU7-compatible node software. Faster target blocks accelerate confirmations in expectation but do not guarantee instant finality.

Block timing and confirmations

The network now targets a block every 25 seconds. This reduces time to reach multiple confirmations under typical conditions. Target spacing is a statistical expectation and real block arrivals remain irregular. Exchanges and payment processors define their own confirmation thresholds.

Issuance and reward schedule

To avoid tripling coin issuance due to more blocks, NU7 lowers the scheduled reward per block and adjusts remaining issuance and halving intervals. The monetary supply trajectory remains broadly aligned with the previous schedule.

Network Sustainability Mechanism

NU7 directs 60% of transaction fees to a public reserve for later reissuance to miners and leaves 40% as immediate miner revenue. The design goal: smooth the decline of subsidy-funded security over time. Reserved fees do not function as immediate miner income and should be evaluated for long-term incentive effects.

Compatibility and deprecations

Node operators must run NU7-compatible clients to remain on the consensus chain. The Zcash Foundation’s Zebra 7 release notes confirm the activation height and consensus changes. NU7 retires support for older version-four transactions, which affects the original Sprout pool.

Operational checks for users and services

Privacy-preserving transfers benefit from protocol improvements when wallets and services support them. Practical next steps: verify node versions, observe block times, confirm service-specific confirmation requirements, and check wallet announcements for NU7 support. Prior updates focused on reliable chain following in Zebra sync work, as covered by NewsBTC. Operational diligence remains necessary after activation.

Featured image: Zcash project emblem used as an illustrative brand mark for Zcash NU7 network upgrade coverage. Source: Zcash project via Wikimedia Commons, Public Domain simple logo.