The Nexus zkVM 3.0

·

The landscape of zero-knowledge proof systems is evolving rapidly, and at the forefront of this transformation stands the Nexus zkVM 3.0—a groundbreaking leap in verifiable computation. This next-generation zero-knowledge virtual machine redefines performance, scalability, and developer experience by combining cutting-edge cryptographic research with a robust, modular architecture built for real-world applications.

A Ground-Up Redesign for Performance and Extensibility

The Nexus zkVM 3.0 is not an incremental update—it's a complete rewrite from the ground up, engineered to overcome the limitations of earlier zkVM generations. Unlike its predecessors (zkVM 1.0 and 2.0), which relied on Nova-based folding schemes, this new version introduces a formally specified, RISC-V-targeted virtual machine optimized for speed and correctness.

Backed by StarkWare’s Stwo prover—a record-breaking STARK prover known for its lightning-fast performance—the Nexus zkVM 3.0 achieves up to ~1000x faster proving times compared to previous iterations. This dramatic improvement makes it feasible to deploy zero-knowledge proofs at scale across demanding use cases like zkML, blockchain validation, privacy-preserving computation, and secure auditing.

👉 Discover how high-performance proving can transform your application development.

At the core of this breakthrough is a redesigned machine architecture featuring:

This combination enables developers to compile general-purpose Rust programs into verifiable proofs with minimal overhead and maximum efficiency.

Core Innovations: Formal Specification and Proving Architecture

One of the defining features of the Nexus zkVM 3.0 is its formal specification, publicly available at specification.nexus.xyz. This document provides a rigorous mathematical description of the system, including:

These components work together to create a concise, sound proof that every step of program execution was performed correctly, while minimizing computational overhead.

By integrating with the Stwo prover, the zkVM leverages state-of-the-art STARK technology to generate succinct, trustless proofs. Stwo’s optimized polynomial commitment scheme and recursive proving capabilities allow the Nexus zkVM to handle complex computations efficiently, making it one of the most performant zkVMs available today.

Our commitment to open science means the entire implementation is source-available on GitHub, allowing researchers, developers, and auditors to inspect, verify, and contribute to the system’s evolution.

Developer-Centric Design: Building with the Nexus SDK

The Nexus zkVM 3.0 prioritizes developer experience without sacrificing power or security. With the Nexus SDK, proving arbitrary Rust programs becomes intuitive and accessible—even for those new to zero-knowledge development.

Developers work with two components:

  1. Guest Program: Runs inside the zkVM and contains the logic to be proven.
  2. Host Program: Controls the zkVM, triggers proof generation, and verifies results.

To get started:

$ cargo nexus host nexus-host

This command scaffolds a project structure with both host and guest environments:

./nexus-host
├── Cargo.toml
└── src
    ├── main.rs              # Host program
    └── guest
        └── src
            └── main.rs      # Guest program

Example: Proving Multiplication

Here’s a simple guest program that multiplies two integers—one public, one private:

#![cfg_attr(target_arch = "riscv32", no_std, no_main)]
use nexus_rt::println;

#[nexus_rt::main]
#[nexus_rt::public_input(x)]
fn main(x: u32, y: u32) -> u32 {
    println!("Read public input: {}", x);
    println!("Read private input: {}", y);
    x * y
}

And here’s how the host program compiles, proves, and verifies execution:

use nexus_sdk::{
    compile::{cargo::CargoPackager, Compile, Compiler},
    stwo::seq::Stwo,
    ByGuestCompilation, Local, Prover, Verifiable, Viewable,
};

const PACKAGE: &str = "guest";

fn main() {
    println!("Compiling guest program...");
    let mut prover_compiler = Compiler::new(PACKAGE);
    let prover: Stwo = Stwo::compile(&mut prover_compiler).expect("failed to compile");

    print!("Proving execution of vm... ");
    let (view, proof) = prover.prove_with_input(&(5u32), &(3u32)).expect("proving failed");

    assert_eq!(view.exit_code().unwrap(), 0);
    let output: u32 = view.public_output().unwrap();
    assert_eq!(output, 15);

    println!("output is {}!", output);
    println!(">>>>> Logging\n{}\n<<<<<", view.logs().unwrap().join("\n"));

    print!("Verifying execution...");
    proof.verify_expected(
        &5,     // public input x
        0,      // exit code
        &15,    // output z
        &prover.elf,
        &[],
    ).expect("verification failed");
    println!(" Succeeded!");
}

Running cargo run -r produces:

Proving execution of vm... output is 15!
>>>>> Logging
Read public input: 5
Read private input: 3
<<<<<
Verifying execution... Succeeded!

This seamless workflow lowers the barrier to entry for building verifiable applications.

Real-World Applications and Evaluation

The Nexus zkVM 3.0 powers a wide range of applications where trustless verification is critical:

Benchmarks included in the formal specification show significant improvements in both time and memory usage compared to native execution overhead. Microbenchmarks confirm the efficiency of Stwo integration, while end-to-end tests validate performance on full Rust programs—proving readiness for production deployment.

👉 See how fast proving can accelerate your next project.

Frequently Asked Questions (FAQ)

Q: What makes Nexus zkVM 3.0 different from other zkVMs?
A: It combines a formally verified RISC-V architecture with Stwo’s ultra-fast STARK prover, achieving ~1000x speedups over older folding-based systems while maintaining full programmability.

Q: Can I run existing Rust code on the zkVM?
A: Yes—any Rust program compilable to RISC-V can be adapted for use as a guest program with minimal changes.

Q: Is the zkVM open source?
A: While not fully open-source under a permissive license, it is source-available on GitHub for inspection and development purposes.

Q: How does memory management work in the zkVM?
A: It uses a dynamic memory model with a modified Harvard architecture, enabling efficient "prove only what you use" semantics via optimized memory checking arguments.

Q: What role does Stwo play in the system?
A: Stwo serves as the backend prover, generating STARK proofs that verify correct execution of zkVM programs with minimal latency and resource consumption.

Q: Where can I find documentation and examples?
A: Comprehensive guides and tutorials are available at docs.nexus.xyz.

The Future of Verifiable Computation

The Nexus zkVM 3.0 marks a pivotal moment in the evolution of zero-knowledge systems. By unifying formal correctness, high performance, and developer accessibility, it opens new possibilities for trustless computing across industries.

Ongoing work focuses on further optimizing proving speed, expanding language support, and enhancing compatibility with decentralized networks and Layer 2 solutions.

Whether you're building privacy-preserving AI models, secure financial protocols, or transparent governance systems, the Nexus zkVM 3.0 offers a powerful foundation for verifiable logic.

👉 Start building with high-performance zk proofs today.

The future of computation isn’t just fast—it’s provably correct. And it starts now.