ICICLE Integrated Provers

ICICLE has been used by companies and projects such as Celer Network, Consensys Gnark, EZKL, ZKWASM, Tachyon by Kroma Network, and others to accelerate their ZK proving pipeline.

Many of these integrations have been collaborative efforts between Ingonyama and our partners, providing valuable insights into designing GPU-based ZK provers.

If you want to dive deeper into these integrations or explore how ICICLE can accelerate your ZK proving pipeline, you’re in the right place.

A Primer to Building Your Own Integrations

Lets illustrate an ICICLE integration, so you can understand the core API and design overview of ICICLE.

Engineers typically rely on cryptographic libraries to implement ZK protocols, using efficient primitives as building blocks. ICICLE is one such library, uniquely designed from the ground up to run on GPUs. Its Rust and Golang APIs abstract away the complexities of CUDA, enabling developers with no GPU experience to get started quickly and efficiently.

A developer may use ICICLE with two main approaches in mind:

1. Drop-in replacement approach.
2. End-to-End GPU replacement approach.

The first approach to GPU-accelerating your Prover with ICICLE is quick to implement but comes with limitations, such as reduced memory optimization and limited protocol tuning for GPUs. While it’s a strong starting point, those looking to fully harness GPU acceleration should explore more advanced solutions.

An end-to-end GPU replacement involves performing the entire ZK proof on the GPU. This approach minimizes latency, fully leverages GPU acceleration, and requires adapting the protocol to be more GPU-friendly. While redesigning your prover this way demands additional engineering effort, the results are well worth it!

Using ICICLE Integrated Provers

This section explains how developers can run existing circuits on ICICLE-integrated provers.

Gnark

Gnark officially supports GPU proving with ICICLE. Currently only Groth16 on curve BN254 is supported. This means that if you are currently using Gnark to write your circuits you can enjoy GPU acceleration without making many changes.

info

Currently ICICLE has been merged to Gnark master branch, however the latest release is from October 2023.

Make sure your golang circuit project has gnark as a dependency and that you are using the master branch for now.

go get 	github.com/consensys/gnark@master

You should see two indirect dependencies added.

...
	github.com/ingonyama-zk/icicle v0.1.0 // indirect
	github.com/ingonyama-zk/iciclegnark v0.1.1 // indirect
...

info

As you may notice we are using ICICLE v0.1 here since golang bindings are only support in ICICLE v0.1 for the time being.

To switch over to ICICLE proving, make sure to change the backend you are using, below is an example of how this should be done.

// toggle on
proofIci, err := groth16.Prove(ccs, pk, secretWitness, backend.WithIcicleAcceleration())

// toggle off
proof, err := groth16.Prove(ccs, pk, secretWitness)

Now that you have enabled WithIcicleAcceleration backend simple change the way your run your circuits to:

go run -tags=icicle main.go

Your logs should look something like this if everything went as expected.

13:12:05 INF compiling circuit
13:12:05 INF parsed circuit inputs nbPublic=1 nbSecret=1
13:12:05 INF building constraint builder nbConstraints=3
13:12:05 DBG precomputing proving key in GPU acceleration=icicle backend=groth16 curve=bn254 nbConstraints=3
13:12:05 DBG constraint system solver done nbConstraints=3 took=0.070259
13:12:05 DBG prover done acceleration=icicle backend=groth16 curve=bn254 nbConstraints=3 took=80.356684
13:12:05 DBG verifier done backend=groth16 curve=bn254 took=1.843888

acceleration=icicle indicates that the prover is running in acceleration mode with ICICLE.

You can reference the Gnark docs for further information.

Halo2

Halo2 fork integrated with ICICLE for GPU acceleration. This means that you can run your existing Halo2 circuits with GPU acceleration just by activating a feature flag.

To enable GPU acceleration just enable icicle_gpu feature flag.

This feature flag will seamlessly toggle on GPU acceleration for you.