Zcash Shielded News | Vol.31 ⓩ
What's Project Tachyon + News, ZCG | Meeting Minutes (05/12/2025), ZF Engineering Update: 2025 Sprint 9 (Apr 28 - May 9), Maximizing Time. ECC Update & More
Zcash Shielded News is a community article format based on the weekly Zcash Ecosystem Digest Newsletter.
Providing insight on current events and informing the community about important news in the Zcash ecosystem.
Check out the best Highlights below
In 2024, Sean Bowe left the Electric Coin Company after nine years with the organization. Sean is also one of the key contributors to the discovery of Halo 2, which marked a significant advancement for Zcash technology and for those leveraging zero-knowledge (ZK) proofs in their own projects.
Today, many projects use “ZK” as a marketing term, with little to no regard for actual user privacy. However, in Sean’s view, it is possible to achieve both: a private digital payment network that can scale to billions of users.
Zcash is a strong project when it comes to privacy and security. However, its scalability still needs improvement — and that’s exactly what Project Tachyon aims to address.
Here are some of the features that Tachyon is bringing to Zcash.
Proof-Carrying Data (PDC)
PCD is a cryptographic technique where data carries its own proof of correctness. When the data is updated, the proof remais valid and can be extended. It enables wallets and transactions to maintain compact proofs of validity as they process blocks, allowing validators to prune old blockchain state safely.
Oblivious Synchronization
This is a new wallet sync model where external services can assist with synchronization without learning any private data. This prevents wallets from needing to download and scan the entire blockchain, reducing bandwidth, CPU, and sync time, and enabling scalability to millions of users.
Out-of-Band Secret Distribution
Instead of embedding encrypted note info in transactions, senders use off-chain channels (like apps, chat, or web) to deliver secrets to recipients. This eliminates ciphertext from transactions, reducing block size and improving scalability while aligning with real-world payment flows.
More Private Nullifier Derivation
Project Tachyon allows a change in how nullifiers (used to prevent double-spending) are computed to avoid leaking metadata about wallet state or note position. This prevents syncing services from inferring wallet activity, making PCD-based sync safe and private.
New Cryptographic Accumulator.
This is a redesigned accumulator that supports batch insertion and efficient (non-) membership proofs, compatible with PCD and allows most blockchain history to be summarized and pruned, increasing efficient for wallets and validators alike.
Proof Aggregation
This can combine multiple zk-SNARKs into a single, compact proof, using techniques like SnarkPack or PCD and it can greatly increase block capacity, reducing verification time and improving overall network performance.
Enhanced Payment Protocol (Orchard ++)
This is an upgrade to the existing Orchard protocol allowing wallet state (as PCD) to be included in transactions.
It also enables validators to ignore past blockchain data, verifying only recent changes — a critical step toward succinct blockchains and higher throughput.
The future of private, scalable finance is within reach — and Tachyon brings us one giant leap closer.
Few days ago, Sean posted a new article called ‘‘Tachyaction at a Distance’’ giving new tech details about the project. You can read here.
Keep in mind that: This design significantly simplifies Zcash's shielded protocol while enabling massive scalability through proof aggregation, state pruning, and cleaner cryptography — all without compromising user privacy.
Excited? We are!. 😁🎉
On May 12th, ZCG published the notes from the latest grant proposal review and the brainstorming session.
Participants:
Ledger Live Integration
Zondax aims to integrate the new Zcash Ledger Shielded app with Ledger Live, initially focusing on transparent transaction support, with shielded transaction integration planned for a later phase. They are requesting $95,000.
The committee is still deliberating on this grant.Key takeaways from Jason and Pacu's call with Ledger:
Ledger will fix the Sapling input issue for free.
Ledger will submit a retroactive grant proposal for shielded support to align with community expectations.
ZCG is open to discussing ongoing maintenance and support funding for Zcash on Ledger devices.
A Ledger representative will soon engage on the forum to confirm long-term support and address the above items.
Zcash Global Turkish (Q2 2025)
This project aims to introduce Zcash to a wider audience in Turkey, raise awareness about the importance of financial privacy, and build a strong, sustainable Turkish Zcash community.
It focuses on education, content creation, and community building through platforms like Telegram, Twitter, YouTube, and blogs, supported by local events.
The requestor is asking for $10,400 for three months of funding.
ZCG members are asked to provide feedback and vote. Jason noted the group has discussed and decided to approve the grant.
The team has done a good job, with positive feedback from Artkor’s Turkish community survey, showing value in the team’s content and support for continuing the project.
Unanimous approval.
Zcash Nigeria (Q2 2025)
Zcash Nigeria seeks $9,600 to expand education, events, and social media outreach, aiming to grow community engagement and ZEC adoption.
While Jason, Brian, and Gguy support the grant, Zerodartz expresses concerns about impact and wants more localized, goal-driven activity. The team is open to feedback and improvement.
Unanimous approval.
AirGap Cold Wallet Solution
AirGap is an open-source, self-custody wallet that uses a two-app system—AirGap Vault for offline key storage and AirGap Wallet for transaction management—transforming any spare smartphone into a secure, air-gapped cold wallet.
It offers features like human-verifiable seed generation, complete offline operation, BIP-39 passphrases, BIP-85 support, and social recovery.
The team has experience with shielded Sapling transactions for Tezos and is requesting $100,000. ZCG members are asked to provide feedback and vote.
Brian, Gguy, and Zerodartz all reject the proposal, citing lack of demand and existing commitments. Jason also votes to reject.
Unanimous rejection.
Brainstorm Session Follow-Ups
Maya Protocol
This is getting very close, possible launch in May.
Lightwalletd Infrastructure.
ZCG is working to migrate Hanh’s infrastructure to ZecHub in the next few months.
Zingo / Qedit
ZCG is struggling with delays in the NU7 upgrade and zcashd deprecation, leading to potentially unsustainable funding extensions for related projects like Qedit, Zingo, and Blockchain Commons.
Grants need defined scopes and endpoints.
If you're a Zcash enthusiast like us, you're probably closely following the updates shared by Pili on the progress of Zebra, FROST, and DevOps.
This week, we received the latest development news from Sprint 9.
Check it out!
During this sprint, the ZF team focused on releasing Zebra 2.3.0.
While the release of Zebra 2.3.0 was delayed due to integration issues with lightwalletd, other development work moved forward. This included finalizing improvements to key RPC methods, advancing support for Unified and TEX addresses, and beginning work on shielded coinbase transactions.
ZF also started integrating Zaino, Zallet, and Zebra for automated testing and introduced a new RPC method to improve mempool event tracking. These efforts are part of the broader strategy to transition smoothly away from zcashd.
ZF also addressed several requested fixes during this sprint. The team improved consistency with zcashd by updating the getblockchaininfo RPC to return chain upgrades in the correct order. They also refined the z_gettreestate RPC to make the finalState field optional and enhanced startup error messages in Zebra to better inform users when state database access fails.
Finally, in order to allow downstream zebra crate consumers to have more control over the versions of their dependencies, they have changed our dependabot settings to only update the Cargo.lock file going forward.
ZF has completed development on the FROST reference implementation, including frost-core, frostd (server), and frost-client, following a successful audit of the server and client components. Future work will depend on requests from wallet developers. A blog post outlining this milestone and next steps is expected later this week.
On DevOps, ZF spent some time investigating the issues with the lightwalletd tests in CI and also started looking into optimising CI compilation times.
Josh delayed this week's update to spend meaningful time with his daughter, emphasizing the importance of prioritizing what truly matters. He reflected on how time is limited and focus is essential.
He expressed concern over crypto's regulatory direction, warning that increasing oversight is leading to capture by traditional financial institutions and state surveillance. KYC flaws and centralized custodianship threaten the ideals of decentralization and privacy.
To improve team productivity, Josh launched a six-week experiment cutting most status meetings, inspired by Andreessen's Guide to Personal Productivity. The goal: Reduce distractions, reclaim focus, and ship code faster.
He closed the update with a clear call to action: Zcashers must cut ruthlessly, think deeply, and build relentlessly — because time is running out. Read more.
Zashi
📱| Zashi Design
Continued Cross-chain Payments design work (SwapKit & NEAR research)
Minor product and engineering edits
Updated designs for Select/Save Recipient and Add New Contact
Collected crypto coin icons for design use
Progressed on Zashi landing page
🍎| Zashi iOS
📈Unique Installs: 7.82k
⬇️Total Downloads: 9.47k
⭐AppStore Rating: 4.9*
Zashi 2.0:
Swap and Pay PoC
SDK with Tor, another iteration with no fallback and default TorClient
UA with no transparent receiver adopted in Zashi with refactor for defaultUA & privateUA
Zashi iOS 2.0.3 release prepared for next week
🤖| Zashi Android
📈Total Install Base: 3.74k
⬇️Total Installs (incl. Open Beta): 18.5k
⭐PlayStore Rating: 4.509*
2 most recurring crashes resolved
Several less recurring crashes resolved
Looking into user-reported issues
Zashi Android 2.0.2 released to Beta and Production
UA with no transparent receiver adopted in Zashi with refactor for defaultUA & privateUA - pushed for testing
preparing Zashi Android 2.0.3 release for next week
Zashi Product Marketing
Published privacy-related communications this week.
🦓| Zcash Core
This week, the team made incremental progress on Zallet, merging
z_sendmanyand advancing the zcashd wallet import.They aim to have an MVP ready next week with full wallet functionality and key import from zcashd completed.
🦓| Other
Josh participated on a panel at Consensus called “Privacy is Normal.”
Attended an intimate dinner with other crypto leaders - great conversations and a few follow-ups will come.
Met with a Congressional office and discussed the importance of code-as-speech to keeping innovation in the US.
Josh participated in a podcast with Shielded Labs and Alex from ZF.
Pacu shared new updates from Z3 (formerly Zcashd Deprecation)
The community has voted to prioritize the development of new funding mechanisms, which will impact the deprecation of Zcashd and the deployment of NU7.
ZCG and core ecosystem developers are collaborating to assess the extent of this impact and how it will influence ZCG’s 2025 planning. Some of this discussion took place during the “Open Discussion” segment of the May 15th Arborist Call.
Zebra
The Zebra team fixed several integration issues in
gettreestate,getblockandvalidateaddressand they are working on mempool changes and mine to orchard which will not only help miners but according to what Zaino devs have been discussing it would speed up some tests as well.Alfredo has been integrating all the Z3 components and we will know know about it in the Zallet section.
Zaino (ZingoLabs)
Status: On-track
This week’s focus has been on updating Zcash dependencies for the Zaino team. Zaino development now uses the latest versions of the official (unforked)
librustzcashandzebra.Dropping a
librustzcashfork is a positive step forward!
The Zaino team is nearly done planning the re-architecture of the chain cache and is now moving into the implementation phase.Zaino folks have also started to look into their continuation grant which features block explorer support pieces.
In-Memory backend wrap up
Status: Pending Review
This has been somewhat overlooked—reviews are still needed for PR #1634 in librustzcash.
Zallet full node wallet
Status: delayed (but rapidly catching up)
ECC has notified a deviation of 2 months from the original schedule. tracking work on this repository.
Despite juggling multiple priorities—like C&C funding, lockbox disbursement, address rotation, and UA transparent receiver removal—ECC continues to make steady progress on Zallet. OpenRPC is now fully integrated, and
z_sendmanyis working, though not yet feature-complete compared to Zcashd. Wallet import from Zcashd is progressing but slower than expected.Meanwhile, Alfredo from the Zcash Foundation has been testing Zallet, Zaino, and Zebra together, uncovering and helping resolve several integration issues.
Wallet Export format + ZexCavator
Status: On-track
bc-shannon shared an update on the challenges with ZeWIF integration, which has been more complex than expected.
Nuttycom has been deeply involved in integrating it into Zallet and contributing upstream.
The Zcashd part of ZeWIF is particularly difficult due to its deep historical context, which is essential for converting
wallet.datfiles into an interoperable format.This topic was discussed in the May 15th Arborist Call, highlighting the unexpected hurdles and extra work. Jason and Pacu also met with Blockchain Commons and plan to meet with the Zallet team to plan next steps.
Block Explorer Support
Pacu began by syncing a testnet Zcashd and setting up the Block Explorer. With Jason McGee initiating a conversation with CoinMarketCap to address inaccurate Zcash data affecting downstream users of their API, this work became especially timely.
Pacu also submitted a small PR that is now awaiting review.
Yesterday, Shielded Labs hosted a Community Call on Zcash Global to present the Crosslink Milestone #2 Workshop. The session featured nearly 10 speakers and active participation from the community via the chat, where attendees followed step-by-step instructions to run their fork of Zebra in “Mainnet Shadowing Mode.” This mode utilizes a BFT chain to reach consensus on the highest block in the PoW chain considered “finalized.”
The primary goals of the call were to introduce the fundamentals of Crosslink, stress-test Shielded Labs’ early prototype, and foster collaboration in a fun, hands-on environment.
Community members (Noders) came together — and we did it!
For more details about the event, check out this thread. The recording will be available soon.
Congratulations to everyone involved! 💛
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