Aztec Ships Client-Side Proving on Ethereum, Putting Private Smart Contracts on Users' Own Devices

Aztec, the privacy-focused layer-2 network built on Ethereum, has moved its long-running privacy roadmap onto live infrastructure. The Alpha V5 release introduces client-side proving, meaning the zero-knowledge proof that keeps a transaction private is generated on the user's own device rather than by centralized proving servers. That design choice is the difference between privacy as a service someone else operates and privacy the user controls from end to end.

The performance figures matter because they determine whether confidential execution is usable at consumer scale. Aztec reports block times cut from 14 seconds to six, rollup proof-verification costs down roughly 40 percent, and the average fee for a private token transfer under $0.05. The network's transaction model splits execution into a private phase proven on the client and a public phase settled on-chain, letting applications combine hidden and visible state within a single call.

The launch arrives in the middle of a contest over who controls confidentiality. Competing designs from Miden and others frame privacy as a prerequisite for serious institutional use, while regulators in several jurisdictions treat privacy tooling with suspicion. Aztec's answer is architectural. By moving proof generation onto user devices, it removes the central operator that a regulator could pressure or that could identify users, at the cost of demanding more from the user's hardware.