ZisK Fibonacci Example

A Fibonacci sequence calculator running inside the ZisK zkVM. The guest computes Fibonacci(n) and the host generates a zero-knowledge proof of that computation.

What It Does

1. Sends n=10 as input to the guest
2. Guest computes Fibonacci(10) = 55 inside the ZisK VM
3. Generates a VADCOP STARK proof of the computation
4. Verifies the proof

Project Structure

fibonacci/
├── Cargo.toml              # Workspace
├── guest/
│   ├── Cargo.toml
│   └── src/main.rs         # Runs inside zkVM: computes Fibonacci(n)
├── host/
│   ├── Cargo.toml
│   ├── build.rs            # Cross-compiles guest to RISC-V ELF
│   └── src/main.rs         # Sends input, proves, verifies
└── lib/
    ├── Cargo.toml
    └── src/lib.rs           # Shared types (FibResult)

Prerequisites

• ZisK v0.16.0 installed via ziskup
• Linux x86_64 (required for proof generation)
• 16 GB RAM minimum, 64 GB recommended

Run

cargo run --release

[1/3] Executing...
      Fibonacci(10) = 55
      Cycles: 10645
[2/3] Generating proof...
[3/3] Verifying...
      Proven: Fibonacci(10) = 55
      Proof verified!

How It Works

Guest (guest/src/main.rs)

Runs inside the ZisK VM:

1. Reads n from the host via io::read()
2. Computes Fibonacci(n) iteratively
3. Commits the result via io::commit() (becomes public output in the proof)

Host (host/src/main.rs)

Runs natively on your machine:

1. Sends n=10 as input to the guest
2. Executes the guest in the VM (fast sanity check, no proof)
3. Proves the execution (generates a VADCOP STARK proof)
4. Verifies the proof against the verification key

Shared Types (lib/src/lib.rs)

• FibResult - n and the computed value (committed as public output)

Build Flow

cargo run --release does everything:

1. host/build.rs cross-compiles the guest to a RISC-V ELF
2. include_elf!("guest") embeds the ELF into the host binary
3. The host binary runs: execute, prove, verify

License

MIT