Zcash NU7 to Cut Block Times as Builders Map Out Bigger Privacy Scaling Plan

NU7 brings the first scaling step

The upcoming release is Zcash’s ninth major network upgrade. Its most immediate effect is faster block production, which the project says can raise throughput without increasing block size. Ojha said this would make higher-throughput proof-of-work operation possible while keeping Zcash on its existing consensus model.

The tradeoff is that proof-of-work block timing remains probabilistic. According to the roadmap discussion, even with a 25-second average, about 1% of blocks could arrive in roughly 250 milliseconds, while another 1% could take longer than 110 seconds. More advanced throughput work, including networking improvements such as erasure coding and smarter gossip between nodes, is described as work for the next two years rather than part of NU7 itself.

Private wallet syncing is a central challenge

A major obstacle for privacy chains is helping wallets determine when they have received funds. Because Zcash shielded addresses hide sender and recipient information, wallets cannot simply ask a server for an account balance in the way that many transparent systems can.

The roadmap points to private information retrieval, or PIR, as a solution. Under that model, a wallet sends an encrypted query to a server that stores chain data, and the server returns the relevant result without learning what was requested. The article says this approach has become more practical because PIR relies heavily on matrix-vector computation, an area where GPUs have become cheaper and faster amid the AI boom.

The trusted-middleman concern remains, but builders compare the model to RPC infrastructure on Ethereum, where multiple providers can exist and users can switch among them. According to the source article, Zcash has already used PIR in a recent coinholder vote, which it describes as a first for a crypto project.

Tachyon targets proof verification and state growth

Another key part of the roadmap is Tachyon, a cryptography overhaul intended to address two separate bottlenecks. The first is proof verification. At present, a full node checks each shielded transaction’s zero-knowledge proof individually. Tachyon is developing recursive SNARKs that would aggregate those checks, allowing a node to verify rolled-up proofs rather than many standalone ones in sequence.

The article says that proof aggregation could deliver at least a 5x scaling improvement immediately once deployed. It compares the idea to the batching model used by ZK rollups on Ethereum, although Tachyon remains under development rather than live on mainnet.

Tachyon is also meant to reduce state bloat. Every shielded spend creates a nullifier to stop double-spending, and that forces privacy chains to retain large amounts of historical data. The proposed approach would compress state so full nodes keep roughly the last month of live state, while older history could still be queried trustlessly when needed.

RPC economics and the next confirmed milestone

The roadmap also includes a proposed private subscription model for RPC access. In the concept described, users would prepay for a set number of requests and receive one-time tokens. Each query would consume a token using Zcash’s double-spend-prevention techniques, allowing a provider to verify that a request is covered without learning which subscriber made it. The article characterizes this idea as still conceptual, though solvable.

For now, the only confirmed milestone is NU7 activation overnight on Nov. 5 to 6 UTC. PIR is described as already in use in at least one limited setting, while Tachyon’s code is being integrated into the Zakura full node without a public mainnet launch date. The remaining pieces, including broader throughput improvements and RPC subscriptions, are framed as part of a multi-year effort to scale private ZEC payments.