zakura

Zakura has announced an experimental network layer P2Pv2 for Zcash nodes, intended to replace the old protocol inherited from Bitcoin. This layer combines high-throughput networking, resource control, and a consensus engine tested for properties, allowing developers to add services without permission. Zakura states that approximately 50,000 transactions per second require each full node to continuously receive about 100MB/s of block data, while the 25-second block of NU7 can carry a maximum of 2MB, with existing network throughput differing by more than a thousand times from this rate. Tachyon can reduce the proof after entering the block, but the network still needs to propagate a large number of individual transactions.P2Pv2 replaces the protocol stack from about a decade ago with protocols that can be optimized for latency, throughput, or robustness, allowing a secure connection to carry multiple independent services. The transport layer uses its own zakura-quic, based on quinn-proto, utilizing QUIC and TLS 1.3, and authenticating peers with Ed25519 node identity. Related changes remove the dependency on Iroh, allowing nodes to configure socket buffers, flow control windows, timers, and connection admission before the TLS handshake. The new transport directly connects to peer addresses without using relays, external address lookups, automatic port mapping, or QUIC NAT traversal. Nodes sign identities, addresses, protocol scopes, and service IDs, allowing clients to find peers based on specific services.The independent component zakura-header-chain verifies block headers and retains competing branches in a directed acyclic graph, selecting the best qualified chain. Block synchronization schedules requests based on the delivery rates measured by each peer, and a verified commitment tree is used to skip the reconstruction of Sapling, Orchard, and Ironwood trees for each block. Currently, the Mainnet still defaults to the old P2P stack, while the Testnet and Regtest run dual stacks by default, with the native protocol version being p2p-v2/3. Zakura notes that P2Pv2 still has known denial-of-service risks and has not yet become a hardened trust boundary; production hardening, resource control, and block relay protocols are still in progress.

The Zakura team, which operates the Zcash network, released a technical article stating that they plan to allocate a unique viewing key for each ZEC exchange completed through NEAR Intents, in order to block future quantum computers from exploiting public refund addresses to piece together user payment histories. NEAR Intents supports cross-chain token exchanges, and when users exchange the privacy coin ZEC for USDC, the service will publish a Zcash address for the user on the NEAR public blockchain, which will be used to return any unused ZEC.The Zcash address contains a public key generated by the wallet's viewing key, which cannot be reverse-engineered by ordinary computers, but large quantum computers running Shor's algorithm could theoretically deduce the key from the address. Zcash wallets can generate multiple seemingly unrelated addresses, but they typically share the same viewing key. Once an attacker cracks it, they can associate all payments received by the account and read the amounts and notes. Zakura's solution allocates a unique viewing key for each exchange, while the spending key remains in the user's main account. Even if the future refund address is compromised, the attacker would only be able to see payments related to that specific exchange.This design also addresses a practical issue: wallets conducting hundreds of exchanges would generate hundreds of keys, requiring each key to scan the entire Zcash chain during backup recovery. Zakura's solution is a privately queryable database that uses private information retrieval technology, so when the wallet inquires about the refund destination, the database will not know the address being queried. Zakura claims that wallets built on its open-source library (including Vizor) will be able to add this feature in the coming weeks, and hardware wallets will follow after firmware support, ahead of the January quantum-resistant payment target set by Zcash developers this month.

The privacy coin project Zcash officially stated that Zcash now has two independent full node implementations, both executing the same rules, namely Zebra and Zakura.Zcash also raised the question: Does the second client truly change the decentralization of the network, or is computing power still the only key factor? Zebra is the Rust full node implementation supported by the Zcash Foundation, while Zakura is another independent full node client.

According to CoinDesk, Zcash developers are integrating part of the proposed scaling upgrade code, Tachyon, into the software already in use to prepare for a large number of privacy transactions in the future. This component is named Udon, originally developed as part of Project Tachyon.According to Sean Bowe, the head of Project Tachyon, Udon was released on Monday to Zakura Common, which is a cryptographic library shared by Zakura and other Zcash projects. Common is responsible for handling some of the heavy mathematical computations behind creating and verifying privacy transactions, with Zakura being jointly developed by Bowe's team and Dev Ojha's Valar Group.Zcash wallets need to prove the validity of a privacy payment without disclosing the payer, payee, or amount, and the computers running the network subsequently verify that proof. According to CoinDesk's report in August, previous improvements to Common have reduced the time to create a privacy transaction from over 3 seconds to under 200 milliseconds in some tests.If privacy payments become more common, these computers will need to handle more data. Udon brings some of the computational requirements for the proposed scaling upgrade of Tachyon into Common, allowing developers to continue building on the already accelerated code. Udon has been released as software, but the upgrade has not yet been activated on Zcash.Bowe and Ojha's long-term goal is to exceed 50,000 payments per second. At this rate, they estimate that current cryptography will allow each Zcash node to receive over 500 MB of data per second.

The Zcash full node client team, Zakura, has released Zakura Common, a set of cryptographic and protocol libraries for the Zcash ecosystem. Official benchmarks show that the proof generation speed on mobile has increased by over 14 times (over 5 times on desktop), Sinsemilla hash speed has increased by over 21 times, decryption trial speed has increased by over 1.5 times, and zk-SNARK verification speed has increased by 4 to 8 times; in many cases, the waiting time for wallet transaction creation can be reduced from over 3 seconds to under 200 milliseconds.This upgrade does not require a network upgrade and has been open-sourced under the MIT/Apache 2.0 dual license. Zakura 1.3.0 will switch to this technology stack.

Zcash has launched a new full node, Zakura, maintained by a team independent of the Zcash Foundation. It is released as a trimmed version of Zebra for fast synchronization and is compatible with the old zcashd client. This client will reach the end of its lifecycle. Zakura is one of the components of Zcash's scalability efforts, working alongside Project Tachyon and private information retrieval research, aiming to increase network throughput to Visa and Mastercard levels by reducing verification data and eliminating wallet performance bottlenecks.Zakura also supports the Ironwood (NU6.3) upgrade, which will be activated on July 28. This upgrade introduces a turnstile mechanism to limit withdrawals from the Orchard shielded pool and control the potential generation of counterfeit ZEC due to long-term soundness bugs.