Key Takeaways
Zebra: Sync reliability continues to improve, alongside peer scoring, mining-template generation, verification performance, CI work, and the first NU7 implementation changes.
Core Libraries: Performance improvements are underway for Pasta curves and Sinsemilla, while ZIP 248 has landed with contributions from the Zcash Foundation.
Zcash Shielded Assets: Halo 2 PR #887 has been merged, clearing an important dependency for the ZSA circuit, while Orchard and librustzcash integration continues.
Zaino: A major refactor is nearing completion, focused on sync performance, reliability, and usability, with serving performance now receiving more attention.
Network Sustainability Mechanism: Poll results favored preserving Zcash’s halvings, with February 2031 selected for the start of reissuing ZEC removed from circulation. Shielded Labs is now working toward implementation in Zebra and Zakura.
Crosslink: Development continues toward another network restart around the end of September, incorporating consensus, staking, finalizer, and slashing improvements.
Fees: A proposed change would lower the marginal fee to 1,000 zatoshis and increase the weight ratio cap to 10×.
Formalization: Review of Zakura’s Halo 2 Action circuit proofs continues, alongside work to generalize the proofs across prover implementations.
Nym × Zcash: Nym has completed network-privacy tooling for Zcash wallets, with Zingo and Zkool already integrating the work.
Zebra: Sync, Validation & NU7
Work on Zebra continues across sync reliability, consensus validation, performance, and preparation for NU7.
Recent changes address issues that could stall sync progress or cause unnecessary sync restarts. Consensus checks affected by the recent transaction-format refactor have also been restored, with additional regression testing added to help prevent similar issues from returning.
RPC accounting has received further safety improvements as well.
On the performance side, development is focused on better peer scoring and stall detection, faster mining-template generation through precomputation, and caching to improve verification performance. CI reliability and execution speed are also being improved.
Initial NU7 implementation work has now started, with an early PR beginning to introduce the code required for the upcoming network upgrade.
Core Libraries & ZIP 248
Performance work is also moving deeper into the Zcash library stack.
Zodl is contributing assembly-level optimizations for the Pasta curves and improvements to Sinsemilla performance, with new crate releases being prepared to bring these changes downstream.
Meanwhile, ZIP 248, which proposes a transaction-format change for NU8, has landed with contributions from the Zcash Foundation.
zcash_client_backend also received improvements covering multi-account functionality and the handling of Tor connections.
QEDIT: Zcash Shielded Assets
Development of Zcash Shielded Assets (ZSAs) continues on top of NU6.3.
A significant dependency has now been completed with the merge of Halo 2 PR #887, bringing in the supporting Halo 2 changes required for the ZSA circuit.
QEDIT has split its Orchard work into stages. The first PR introduces the ZSA circuit without activating it at the protocol level, while a follow-up will add the remaining integration pieces. Work is also continuing to bring the necessary librustzcash changes up to NU6.3.
Another area being explored is tighter integration between swaps and ZSAs. Rather than treating swaps as a separate layer to be added later, the work is looking at how both features could be designed together from the outset and what improvements that approach could enable.
Zingo Labs: Zaino
Zingo Labs is nearing completion of a major Zaino refactor.
The work brings improvements to sync performance, reliability, and usability. With the refactor approaching completion, attention is also shifting toward improving serving performance.
One focus is optimizing compact-block RPCs, helping Zaino serve wallet clients more efficiently.
Network Sustainability Mechanism & NU7
The latest NU7 polling provided clearer direction for the Network Sustainability Mechanism (NSM).
Results showed support for the version of ZIP 234 that preserves Zcash’s existing halvings rather than the alternative that would smooth the issuance curve.
Another question concerned when ZEC removed from circulation should begin returning through future block rewards. Results differed between groups: panelists preferred starting as soon as possible, while coinholders preferred February 2031.
Following discussion among development organizations, February 2031 was selected as the more conservative interpretation of the polling results.
Shielded Labs is now working to implement ZIP 234 and ZIP 235 in Zebra and Zakura, with September 30 given as the implementation target. This begins translating the poll outcome and NSM design into the Zcash node stack.
The latest design also introduces a new value pool that would receive:
60% of transaction fees
Unclaimed mining rewards
These funds would effectively seed the Network Sustainability Mechanism for future block rewards.
Daira-Emma also plans to update ZIP 234 to reflect the latest NSM design changes.
Meanwhile, ZIP 233 requires a transaction-format change, meaning that component is expected to move to NU8 rather than being included in the current NU7 work.
Crosslink
Crosslink development is moving toward another network restart following the August 26 workshop.
Shielded Labs is targeting approximately the end of September for the restart, with several pieces of the system progressing in parallel.
Recent work includes Zebra updates with Ironwood merged, consensus and staking improvements, finalizer commission work, and refinements to slashing logic.
The first nightly test network has also been deployed, providing an environment for continued testing as Crosslink development advances.
Zcash Transaction Fee Changes
Work is progressing on a ZIP proposing changes to Zcash’s transaction fee parameters.
The current proposal would:
Lower the marginal fee to 1,000 zatoshis
Increase the weight ratio cap to 10×
The goal is to land the corresponding node-side changes on the NU7 timeline.
Having support in full nodes first would allow the network infrastructure to handle the lower fee parameters before wallets begin adopting them.
Zcash Formalization
Formal verification work around Zakura continues, with ongoing review of proofs covering the Halo 2 Action circuit.
Current work is addressing remaining gaps while also improving proof elaboration performance.
There is also an effort to generalize the formal proof so it can apply across different prover implementations rather than being tied to a single implementation.
Separately, a blog post covering higher-level security properties is being prepared.
Nym × Zcash: Network Privacy
Nym has completed work enabling Zcash wallets to route their communications through its privacy infrastructure, adding another layer of protection beyond Zcash’s on-chain privacy.
The integration is designed to strengthen wallet protection against global network observers, traffic analysis and timing attacks, and untrusted Lightwalletd endpoints.
Several components have been developed for Zcash integrations, including a Mixnet stream module, a WireGuard-based DVPN, and Nym Wizzle, which provides application-layer protections around wallet syncing and transaction broadcasts.
The components have now been published, with Zingo and Zkool already integrating the work. Discussions with additional wallets, including Zodl, are also underway.
Together, these tools extend Zcash privacy beyond transaction data by addressing what can potentially be learned from the network connections wallets use to interact with the blockchain.
Looking Ahead
The September 17 Arborist Call showed development progressing across several layers of the Zcash stack at once.
NU7 work is beginning to move from design and polling into implementation, with the Network Sustainability Mechanism taking a clearer shape. At the same time, Zebra and Zaino continue to improve node and wallet infrastructure, while ZSA and Crosslink development move forward.
Formal verification and Nym’s network-privacy tooling are also extending the work beyond protocol features alone, with continued attention to security and privacy across the broader Zcash stack.
The next Zcash Arborist Call is scheduled for October 1, 2026 at 15:00 UTC.
https://www.youtube-nocookie.com/channel/UCi01v05DNTUEC_eB0c9rpgQ