BAZK

What is BAZK?

BAZK is a zkSNARK library for Phala Network. It is based on [gramine]. It is designed to be used in the following scenarios:

• Secure Computation: BAZK can be used to perform secure computation on sensitive data, ensuring that the data and computation results remain confidential and have not been tampered with.

What is a Pod?

A Pod is a secure enclave that runs a program within an Intel SGX (Software Guard Extensions) environment and is attested by the Phala Phat Contract. It provides a trusted execution environment for sensitive computations, ensuring that data and code remain confidential.

Typical Pod Operation

• Key Generation: The Pod generates a public-private key pair. The private key remains securely stored within the SGX enclave.

• Remote Attestation: The Pod undergoes SGX remote attestation, a process that verifies the integrity of the enclave and ensures it is running on a genuine SGX-enabled platform.

• Key Validation: The validator Phat Contract validates the Pod's identity and attestation results. Upon successful validation, the contract signs the Pod's public key, endorsing its authenticity.

• Secure Computation and Signing: The Pod executes sensitive computations within the SGX enclave, leveraging the enclave's secure environment to protect data confidentiality and integrity. The Pod can then use its private key to sign the computation results, providing a verifiable proof of execution.

• Result Verification and Signature Validation: The user receives the computation results and the corresponding signature generated by the Pod. Than it can verify the results with the following steps:

  • The user obtains the Validator contract's public key from the contract itself.
  • The user verifies the Pod's public key against the Validator contract's public key. This ensures that the Pod's public key has been endorsed by the Validator contract and is associated with a legitimate Pod.
  • The user verifies the Pod's signature on the computation results using the Pod's public key. This confirms that the results were indeed generated by the Pod and have not been tampered with. By performing both of these verification steps, the user can establish confidence in the authenticity and integrity of the computation results provided by the Pod.

What's in this repo?

There are four subdirectories in this repo:

• gramine-image/: Dockerfile for the gramine build tools that is used to build measured pod app.
• pod-validator/: The source code of the validator contract.
• ra-report/: The js source code of the npm package used to generate attestation report and communicate with the validator contract.
• nodejs-app-template/: A template for pod app with attestation example.

Getting Started

Prerequirements

• Docker installed and the docker daemon is running.
• Current user is in the docker group.
• Node.js installed. (Tested version : v16.17.1)
• Act installed. (Tested version : 0.2.9)
• Intel IAS API key and SPID. (You can get it from here. can subscribe to get immediate access to the development environment)

Initialize submodules

git submodule update --init --recursive

Install the dependencies

yarn gramine

Build and deploy the validator contract

First you can build the validator contract by running the following command in the root directory of this repo:

cd pod-validator/
patron build

# When build successfully, you would get an HTTP URL like this:
# https://patron.works/codeHash/7298c937d5a638271892eaa35fda08ee931bcf5b197ff3a8a602e978243443f4

That requires you to have patron installed. If you don't want to install it and the Rust toolchain, you can use the compiled contract from here.

Goto the contract link on patron, click the Deploy with Phala button and follow the instructions to deploy the contract. If everything goes well, you would get a contract address, that would be used in the next step, and a web page to operation with the contract.

Build the pod app

You can clone this repo and develop your pod app based on the template in nodejs-app-template/ directory.

Edit the index.ts to replace the value of VALIDATOR_CONTRACT_ADDRESS with the address you got from the previous step. And maybe replace the rpc endpoint if you deployed it on a different testnet.

To build the template app, run the following command in the root directory of this repo:

cd gramine/
cp -L $(which node) bazk-build/
export IAS_SPID=YOUR_IAS_SPID
yarn gramine build

You would get a measurement result in the log like this:

    0000000000010000-00000001ff463000 [REG:RWX] (free)
Measurement:
    fc7f4aab5436670d2f4b26c71441cdc420a0d7537b68d4d06c1d6b907cf35d57

Add the measurement result to the validator contract

Goto the contract web page and click the allow button, paste the measurement result(don't forget to add the prefix 0x) you got from the previous step click the [Run] button. You will see a line of log in the log panel like this:

[#638695][2023-10-20T04:16:42.157Z] Added: 0xfc7f4aab5436670d2f4b26c71441cdc420a0d7537b68d4d06c1d6b907cf35d57

Deploy on Azure with SGX

• Go to portal.azure.com

• Create a new virtual machine: Standard DC2s v2 (2 vcpus, 8 GiB memory)

• Copy the dist folder from local machine to the VM

export AZURE_SSH_PATH=~/YOUR_VM_SSH_KEY_FILE.pem
export AZURE_HOST_IP=YOUR_VM_IP
yarn gramine deploy-azure

• Connect with SSH

ssh -i ~/gramine-vm_key.pem azureuser@172.190.7.62

Run the pod app

To run the pod app, you need a machine with at least Linux kernel v5.13 and SGX enabled.

cd bazk-build/
sudo docker run --rm --device /dev/sgx_enclave --device /dev/sgx_provision -v`pwd`/dist:/dist -it gramineproject/gramine
cd /dist

Apply the environment variables

export ACCOUNT_MNEMONIC=YOUR_ACCOUNT_MNEMONIC_WITH_ENOUGH_BALANCE
export PINATA_API_KEY=YOUR_PINATA_API_KEY
export PINATA_API_SECRET=YOUR_PINATA_API_SECRET
export SGX_ENABLED=true
export IAS_API_KEY=YOUR_IAS_API_KEY_GOT_FROM_INTEL

Run Phase 1 using SGX (KZG)

./gramine-sgx bazk ./app/index.js ./app/bin/new_constrained challenge 10 256 "my ceremony name" "my ceremony description" 1709221725
./gramine-sgx bazk ./app/index.js ./app/bin/compute_constrained challenge1 response1 10 256
./gramine-sgx bazk ./app/index.js ./app/bin/verify_transform_constrained challenge1 response1 challenge2 10 256
./gramine-sgx bazk ./app/index.js ./app/bin/compute_constrained challenge2 response2 10 256
./gramine-sgx bazk ./app/index.js ./app/bin/prepare_phase2 response2 10 256

Run Phase 1 using Node directly

# --------------------------------
# Notes
# --------------------------------
# 1) New ceremony with new challenge
# index.js ./app/bin/new_constrained challenge <power> <bash> <ceremony name> <ceremony description> <deadline timestamp>
#
# 2) Contribute to the ceremony
# index.js <ceremony id> ./app/bin/compute_constrained <challenge> <response> <power> <bash>
#
# 3) Verify the ceremony and create new challange
# index.js <ceremony id> ./app/bin/verify_transform_constrained <existing challenge> <response> <new challenge> <power> <bash>
#
# 4) Finalize the ceremony and prepare for phase 2
# index.js <ceremony id> ./app/bin/prepare_phase2 <response> <power> <bash>
# --------------------------------

export SGX_ENABLED=false

./node ./app/index.js ./app/bin/new_constrained challenge 10 256 "my ceremony name" "my ceremony description" 1709221725
./node ./app/index.js 1707244846 ./app/bin/compute_constrained challenge response 10 256
./node ./app/index.js 1707244846 ./app/bin/verify_transform_constrained challenge response challenge2 10 256
./node ./app/index.js 1707244846 ./app/bin/compute_constrained challenge2 response2 10 256
./node ./app/index.js 1707244846 ./app/bin/prepare_phase2 response2 10 256

Run Phase 2 using SGX (Groth16)

./gramine-sgx bazk ./app/index.js ./app/bin/new circuit.json circom1.params ./
./gramine-sgx bazk ./app/index.js ./app/bin/contribute circom1.params circom2.params
./gramine-sgx bazk ./app/index.js ./app/bin/verify_contribution circuit.json circom1.params circom2.params ./

Run Phase 2 using Node directly

./node ./app/index.js ./app/bin/new circuit.json circom1.params ./app/ceremonies/p12 12 256 "my ceremony name" "my ceremony description" 1709221725
./node ./app/index.js 1706736894 ./app/bin/contribute circom1.params circom2.params
./node ./app/index.js 1706736894 ./app/bin/contribute circom2.params circom3.params
./node ./app/index.js 1706736894 ./app/bin/verify_contribution circuit.json circom2.params circom3.params ./
./node ./app/index.js 1706736894 ./app/bin/contribute circom3.params circom4.params

Generate circuit files

circom circuit.circom --r1cs
snarkjs rej circuit.r1cs circuit.json

Run App using dev mode

1. Build the app:

$ pnpm gramine build

2. Check the gramine package and copy the .env.example file and edit it with your environment config:

$ cp ./packages/gramine/.env.example ./packages/gramine/.env

** Don't forget to update the SGX ENABLED variable to false

4. Run the app using a initial command

# --------------------------------
# Notes to use the app commands
# --------------------------------
# 1) New ceremony with new challenge
# yarn gramine dev ./app/bin/new_constrained <challenge> <power> <bash> <ceremony name> <ceremony description> <deadline timestamp>
#
# 2) Contribute to the ceremony
# yarn gramine dev <ceremony id> ./app/bin/compute_constrained <challenge> <response> <power> <bash>
#
# 3) Verify the ceremony and create new challange
# yarn gramine dev <ceremony id> ./app/bin/verify_transform_constrained <existing challenge> <response> <new challenge> <power> <bash>
#
# 4) Finalize the ceremony and prepare for phase 2
# yarn gramine dev <ceremony id> ./app/bin/prepare_phase2 <response> <power> <bash>
# --------------------------------

## Base example to create a new ceremony
$ yarn gramine dev ./app/bin/new_constrained challenge 10 256 "my ceremony name" "my ceremony description" 1709221725
$ yarn gramine dev 1708608454 ./app/bin/compute_constrained challenge response 10 256
$ yarn gramine dev 1707244846 ./app/bin/verify_transform_constrained challenge response challenge2 10 256
$ yarn gramine dev 1707244846 ./app/bin/compute_constrained challenge2 response2 10 256
$ yarn gramine dev 1707244846 ./app/bin/prepare_phase2 response2 10 256

Workflows

In order to test the workflows locally, you need to install act.

After install, you can the workflow using the following command:

act -W .github/workflows/build-and-release.yml --artifact-server-path ./.github/workflows/.artifacts/ --secret-file ./packages/gramine/.env --job build

If you want to run in your own environment, you can use the following command:

act -W .github/workflows/build-and-release.yml --artifact-server-path ./.github/workflows/.artifacts/ --secret-file ./packages/gramine/.env -P ubuntu-latest=-self-hosted --job build