Getting Started

This chapter will guide you through setting up your local development environment for Ceno and running your first zero-knowledge program.

Local Build Requirements

Ceno is built in Rust, so you must install the Rust toolchain first.

We also use cargo-make to orchestrate the build process. You can install it with the following command:

cargo install cargo-make

Ceno executes RISC-V instructions, so you will also need to install the Risc-V target for Rust. You can do this with the following command:

rustup target add riscv32im-ceno-zkvm-elf

Installing cargo ceno

The cargo ceno command is the primary tool for interacting with the Ceno zkVM. You can install it by running the following command from the root of the repository:

JEMALLOC_SYS_WITH_MALLOC_CONF="retain:true,metadata_thp:always,thp:always,dirty_decay_ms:-1,muzzy_decay_ms:-1,abort_conf:true" \
    cargo install --git https://github.com/scroll-tech/ceno.git --features jemalloc --features nightly-features cargo-ceno

Building the Examples

The Ceno project includes a variety of examples to help you get started.

You can build all the examples using the cargo ceno command-line tool. Execute the following command in the Ceno repository root directory:

cargo ceno build --example fibonacci

This command will compile the example fibonacci located in the examples/examples directory and place the resulting ELF files in the examples/target/riscv32im-ceno-zkvm-elf/release directory.

Running an Example

Once the examples are built, you can run any of them using the cargo ceno run command. We will run the Fibonacci example.

This example calculates the n-th Fibonacci number, where n is determined by a hint value provided at runtime. For this guide, we will calculate the 1024-th number (corresponding to hint value 10 as 2^10=1024) in the sequence.

Execute the following command in the Ceno repository root directory to run the Fibonacci example with prove/verify:

cargo ceno prove --example fibonacci --hints=10 --public-io=4191

Let’s break down the command:

• cargo ceno prove: This is the command to prove a Ceno program.
• --example fibonacci: This specifies that we want to run the fibonacci example.
• --hints=10: This is a private input to our program. In this case, it tells the program to run 2^10 (1024) Fibonacci steps.
• --public-io=4191: This is the expected public output. The program will verify that the result of the computation matches this value.

If the command runs successfully, you have just run your first ZK program with Ceno! The next chapter will dive into the code for this example.