The Zakura client is the initial step in Zcash's goal to scale from about one private transaction per second to a level comparable to major payment networks.
By Shaurya Malwa|Edited by Omkar Godbole Jul 19, 2026, 5:37 a.m. 5 min readMake preferred on ShareShare this articleCopy linkX (Twitter)LinkedInFacebookEmailMake preferred on SummaryShow- Zakura, a new full node for Zcash, operates independently from the Zcash Foundation and is a fast-syncing fork of Zebra, designed to work with the legacy zcashd client before its July 18 phase-out.
- This software is part of a larger initiative, including Project Tachyon and private information retrieval research, aimed at enhancing Zcash's capacity to reach Visa and Mastercard levels by optimizing verification processes and alleviating wallet performance issues.
- The Zakura node is compatible with the Ironwood (NU6.3) upgrade set to activate on July 28, introducing a mechanism to limit withdrawals from the Orchard shielded pool, addressing a historical bug related to counterfeit ZEC.
Those involved in the Zcash project aspire to compete with major payment processors like Visa and Mastercard by managing tens of thousands of transactions each second while ensuring complete verifiability and robust privacy protections.
The launch of Zakura, a new full node software, marks the beginning of this vision. Released in version 1.0.0, it is supervised by Sean Bowe, a key figure in Zcash's zero-knowledge cryptography, and Dev Ojha, cofounder of Osmosis who currently leads Valar Group. Funding for both teams comes from private donations of ZEC rather than corporate or foundation support.
"Our vision is to facilitate global payments. Mastercard and Visa manage over 50,000 transactions every second; that is our baseline. To achieve that with Zcash's current cryptography, a node would need to handle over 500 MB/s of throughput,” states a blog post. “The existing technology will not suffice. The cryptography our teams are developing will bridge much of that gap.”
A full node functions as the program that maintains a complete copy of a blockchain—in this case, the Zcash ledger—and independently verifies each transaction according to the network's regulations. Zakura is derived from Zebra, the Zcash Foundation's node software, meaning it is based on the Foundation's official code but has been reconstructed.
Consensus rules define the common regulations that each node adheres to, determining which blocks and transactions the network recognizes as valid. If a node applies different rules, it diverges and ceases to follow the same chain as the others.
Pruning, Snapshots, and Compatibility
Zakura includes a pruning feature, enabling the deletion of outdated blockchain data that is no longer necessary, significantly reducing disk space usage. This allows the team to offer pre-packaged versions of the blockchain, roughly 11 gigabytes after removing old data, which new nodes can download instead of retrieving the entire history block by block.
This process can set up a new node in less than two minutes, which the team claims is “680 times quicker.”
Additionally, a compatibility mode mimics the interface of zcashd, the original client that is reaching its end of life on July 18, ensuring that wallets and exchange integrations built for it continue to function seamlessly.
Throughput Goals and the Role of Tachyon
The motivation behind these developments is numerical.
Mastercard and Visa handle upwards of 50,000 transactions per second, a figure described as 'its floor, not its goal.' Current Zcash cryptography would require a node to process and verify over 500 megabytes of data each second to keep pace, since every private transaction generates a proof, which is substantial in size.
This equates to continuously receiving enough data to fill a complete DVD every ten seconds, a feat that no current Zcash software can accomplish. The underlying issue is the reason for each bottleneck.
Bowe's Project Tachyon is addressing this by developing recursive proofs, whereby one proof validates thousands of others, substantially minimizing the amount of data that needs to be verified during consensus.
With Tachyon, a node would only need to verify a single proof instead of thousands, which the team believes could reduce the data requirement for consensus from 100 megabytes per second to 500 megabytes, a target they assert is technically feasible with careful engineering.
Wallet Bottlenecks and Valar’s PIR Approach
Wallets face a distinct challenge. Because Zcash conceals the recipient of a transaction, a wallet cannot inquire a server about which transactions are linked to it without revealing its identity. Consequently, it must download all transactions and check each one, which restricts wallet software to about one transaction per second.
To eliminate this limitation, Valar Group is investigating private information retrieval methods that enable a wallet to obtain its own data from a server without the server being aware of which entries were requested.
Rapid Block Propagation
Rapid block propagation refers to the swift distribution of newly mined blocks across a blockchain network. Zakura is designed to oversee this task.
It must transmit new blocks between nodes quickly enough for high-volume proofs and wallet operations to be effective. The software includes an experimental system aimed at ensuring every block reaches every node in under half a second, although this feature is currently disabled by default.
The immediate test of these concepts is scheduled for late July. The Ironwood upgrade, formally NU6.3, is set to go live on the mainnet at block 3,428,143, approximately 8 a.m. Eastern on July 28, and Zakura will support it from its initial release.
Bowe noted on July 10 that all major organizations are aligned with this timeline, which has been pushed back a week from the original schedule due to requests from exchanges and wallet providers for additional preparation time.
The Development of Ironwood
Ironwood was created in response to a vulnerability that almost compromised Zcash in June. The shielded pools on the network are where transaction amounts and participants are concealed, with zero-knowledge proofs serving as validation evidence.
On May 29, a researcher from Shielded Labs, Taylor Hornby, discovered a soundness flaw in the proof circuit for Orchard, the latest shielded pool, which allowed an attacker to create counterfeit ZEC without any on-chain trace. This issue had existed since Orchard's activation in May 2022.
Developers took emergency measures to disable Orchard, completing this on June 2, before restoring it with a corrected circuit through the NU6.2 hard fork at block 3,364,600 on June 3.
However, this fix could not account for the four years the vulnerability was active. Since a zero-knowledge proof reveals nothing beyond its verification, the blockchain lacks records of Orchard transactions, making it impossible to prove that counterfeit ZEC was never created.
Ironwood aims to rectify this situation. It introduces a so-called ‘turnstile’ at the boundary of the pool to control what can enter and exit, leveraging the public nature of ZEC amounts moving in and out of shielded pools, even when the transactions themselves remain private. By restricting new deposits into the Orchard pool, the turnstile serves as the only exit, effectively trapping any counterfeit coins inside.
In essence, legitimate balances can gradually be withdrawn, while counterfeit coins may be prevented from fully entering circulation. This mechanism ensures that any excess supply is contained at the boundary, thereby restoring the reliability of the token's supply.