Building with Aztec and Noir: The State of Ethereum's zkVM in 2025

Aztec & Noir: An Update on Ethereum's Private Smart Contract Layer

Aztec is building a new privacy-first zkRollup for Ethereum, centered around its powerful zkVM for executing private smart contracts. Powering this platform is Noir, the universal programming language for writing zero-knowledge applications.

With the original Aztec Connect bridge now sunset, here’s a look at what’s changed, how Aztec and Noir work together, and where the project stands in July 2025.

⚠️July 2025

As of July 2025, Aztec remains in active development. Noir tooling and compiler upgrades are ongoing, with developer interest steadily growing. While a public testnet or mainnet has not yet been announced, a local developer sandbox is available for testing.

Why Programmable Privacy Still Matters

Ethereum’s transparency is a strength — but also a limitation for:

• Enterprise payments and payroll
• Encrypted DAO governance
• DeFi applications that require regulatory compliance or selective privacy

Aztec enables selective disclosure, letting developers choose what to reveal — and when — while Noir allows them to express this logic in a developer-friendly syntax.

From Aztec Connect to a Privacy-Native Rollup

Aztec Connect, the team’s initial DeFi privacy bridge, was sunset in March 2023. The focus shifted to building a fully programmable privacy platform.

Aztec now consists of:

• A zkVM-based L2 rollup for confidential execution
• Support for smart contracts with both private and public functions
• The Noir language, which compiles to zero-knowledge circuits

What Is Noir?

Noir is a general-purpose programming language built for zero-knowledge applications. It offers:

• A Rust-inspired syntax
• Modular architecture, adaptable across proving systems
• Developer ergonomics over cryptographic complexity

Developers write in Noir → the code compiles into ZK circuits → which are executed privately on Aztec’s rollup.

What’s the Difference Between Aztec and Noir?

Table 1.1

Aztec provides the infrastructure and zkVM, while Noir defines the logic.
They’re designed to work together — but are distinct components: Noir is a versatile language that can be used for other ZK applications beyond just Aztec.

Where Aztec Fits in the Modular Web3 Stack

Table 1.2

Noir is the interface — Aztec is the execution environment.

What to Expect in H2 2025

Aztec continues to focus on:

• Developer SDKs for building with Noir
• Grants for privacy-first dApps
• Improvements to its zkVM and proof performance
• Support for emerging use cases like identity, payroll, and institutional DeFi

While there’s no public devnet yet, tooling is improving and ecosystem momentum is building.

TL;DR

Aztec is Ethereum’s confidential execution layer — a zkRollup for programmable privacy.
Noir is the developer-friendly language used to write private contracts that run on Aztec.

Together, they bring zero-knowledge privacy to Ethereum — without sacrificing composability or developer experience.