Zcash Sprint 200 TPS: A game between 8MB expansion and anti-quantum defense

According to Woofun AI, the Zcash network is preparing a NU 8 upgrade aimed at completely reframing the performance boundaries of the private chain. Its core goal is to increase the throughput of blocked transactions to 200 transactions per second (200 TPS).

This aggressive technical blueprint was officially launched by community developer ValarDragon in the official forum on November 10, 2026, and the implementation window was locked to the end of January 2027. The proposal not only involves intergenerational changes in the underlying cryptographic defense system, but also attempts to resolve the long-term performance bottlenecks that have constrained Zcash's development through drastic expansion, marking a key step in the project's transformation from simple privacy protection to a high-performance privacy infrastructure.

At the architectural level, the core variables of the NU 8 proposal are to launch a new Tachyon shield pool and directly jump the maximum block limit from the current 2MB to 8MB. This adjustment means that the block size has been increased by 4 times. Compared with the 3MB expansion draft previously discussed by the community, its capacity has increased by about 2.67 times.

Data compiled by Woofun AI shows that this expansion of the computing power base is necessary to achieve the 200 TPS target, but it has also sparked intense debate about node hardware thresholds and continuous bandwidth requirements. Core engineer str4d clearly stated that currently the out-of-band communication (OOB) and private information retrieval (PIR) specifications that light wallets rely on have not been established, and directly advancing the 8MB expansion will significantly increase the data synchronization pressure on mobile light clients, forcing the community to make difficult trade-offs between bandwidth efficiency and throughput.

Furthermore, at the transaction structure level, it is recommended to integrate the ZIP 248 specification to eliminate metadata fingerprints exposed by hardware wallets when adding a blocking pool, thereby blocking the external on-chain analysis path for tracking transactions through differences in device signatures.

The upgrade of the security defense system also showed hierarchical characteristics, with the aim of building a future-oriented anti-quantum defense line. The bottom layer of the Tachyon shielding pool uses an ML-KEM ciphertext encapsulation mechanism to establish an unconditional post-quantum privacy system to ensure that even if future quantum computing has the ability to crack, it will not be able to decipher past transaction maps recorded on the chain. For transparent addresses, the proposal plans to add opcodes that support 128-bit and 192-bit SPHINCS signatures (such as SLH-DSA) to provide pre-protection for transparent assets and Ironwood disaster recovery paths that have not migrated to shielded pools. In terms of governance and agreement details, the proposal advocates abolishing the mechanism of forcing changes to the Consensus Branch ID in every round of upgrades to reduce the fragmentation of adaptation to the wallet ecosystem caused by forks, but str4d warns that this parameter is a key barrier to preventing replay of transactions across forks, and alternatives must be established before abolition.

At the same time, asset pool lifecycle management no longer follows the mandatory shutdown of the Sprout Pool during the NU 7 period, but instead sets a specific point at which the Sapling Pool stops making new deposits, allowing existing users to freely transfer funds to preserve the migration buffer period. Network Sustainability Mechanism (NSM) redistribution nodes have also been adjusted to around Zcash's cumulative 7-round halving, which is estimated to be halved every 4 years, and this move will delay the last-end issuance pressure for 4 to 8 years.

Currently, ValarDragon's proposal is still in the open technical verification phase in the official forum, and there are only about two and a half months left until the target window of the end of January 2027. The development team urgently needs to complete a rigorous technical review around the PIR specification and replay protection alternatives, and after all parties have reached a code consensus, they can finalize the specification and submit it to the community for NU 8 governance voting. Following the Ironwood upgrade, Zcash is once again trying to find a new balance between privacy, performance, and security. The final implementation effect will directly determine the network's competitiveness in the post-quantum era.