Arborist Call #111 | (10/02/2025) | Zcash Protocol Updates
Core Team Updates, Research & Implementation Updates, Open Announcements & Discussion.
The Zcash Arborist Calls are bi-weekly protocol development meetings focused on tracking upcoming protocol deployment logistics, consensus node implementation issues, and protocol research.
This summary focuses on the last call that took place on 10/02/2025
Zcash Foundation – Zebra Updates (Arya)
Added a health check endpoint so tools like Kubernetes can auto-restart Zebra if issues occur.
Restored peer misbehavior tests & added support for querying sidechains via getrawtransaction.
Implemented getnetworkinfo RPC + simplified CI for forks.'
Zebra now advertises mined blocks to all peers fixing issues when blocks were created in quick succession on testnets.
Alex added that ZF also posted a longer engineering update on the forum worth checking out for more technical details.
ECC Core Stack Updates (Kris)
Major milestone: the Rust implementation of the Zcash script interpreter is complete. This powers new P2SH functionality across backend libs enabling multi-sig & lockbox use cases for NU6.1. See ZIP 48 for standards.
The keyholder ceremony for the NU6.1 lockbox disbursement address was successfully piloted by Strad on Wednesday.
Result: the first operational P2SH address in the Zcash ecosystem a foundational step for secure fund management and coordination between orgs.
ECC is finalizing crate releases across the full Rust stack for NU6.1, with a compatible Zcashd release expected within days. This upgrade continues aligning legacy components with the Rust-based architecture that underpins Zcash’s modern protocol direction.
On the wallet side, Zashi is evolving:
New policies for confirmation depth (ZIP 315) 3 confs for trusted, 10 for untrusted UTXOs.
UX updates for one-time-use t-addrs in swaps. Huge props to Strad, Kris, Daira & the ECC team for the massive work behind these releases
ZingoLabs, Zaino Updates ( ZA)
Steady progress on Zallet support and major refactors underway , decoupling Zingo infra from non-test crates and refining APIs to expose fewer upstream types. Block explorer RPCs advancing (2 completed, 5 in progress) with updated config landing soon.
NU6.1 Network Upgrade Activation Prep (Pacu)
NU6.1 is being finalized, with activation height expected to be set today (see ZIP 255 zips.z.cash/zip-0255).
All major components Zcashd 6.1.0, Zebra, and supporting crates are wrapping up for coordinated release later this year.
ECC & ZF will notify exchanges, explorers, and miners about timelines to ensure smooth activation. Work on post-NU6.1 features is already in motion, including memory bundles and Orchard crate improvements paving the way for NU7.
Zallet Alpha outreach continues ,select orgs are testing early builds. Anyone can explore the wallet repo and “Alpha Book” here
https://t.co/ejEDZOxwOB
QEDIT – Zcash Shielded Assets (ZSA) (Pablo)
ECC has merged critical updates for Halo2 gadgets & proofs and Zcash note encryption. Orchard ZSA integration is now ready for review, including major work in LibrustZcash, Zebra, and TX v6.
Zallet Alpha outreach continues ,select orgs are testing early builds. Anyone can explore the wallet repo and “Alpha Book” here https://zcash.github.io/wallet/.
The review spans four key parts: • Orchard ZSA data structures & builder • Orchard ZSA circuit (previously audited by Least Authority
Python test vectors for ZSA • Updated Pczt v2 to support future wallets & hardware integrations Review expected to start within 2 weeks, per Daira and KrisThe review spans four key parts: • Orchard ZSA data structures & builder • Orchard ZSA circuit (previously audited by Least Authority
Python test vectors for ZSA • Updated Pczt v2 to support future wallets & hardware integrations Review expected to start within 2 weeks, per Daira and Kris.
On feature flags discussion around merging ZIP 233 (NSM) and NU7 flags. Kris clarified: Zcash unstable is a config flag, not a feature flag. Pablo suggested unifying to simplify logic, but consensus: keep separate for now until confirmed in NU7.
Alfredo raised good questions on Sapling crypto scope & test vector reviews. Pablo emphasized test vectors act as reference implementations, easy to review vs Rust code. Plan: collaborate with Zcash Foundation for cross-org review support a positive step for transparency.