zkEVM Prover

zkEVM proof generator

General info

The zkEVM Prover process can provide up to 3 RPC services and clients:

Aggregator client

• It connects to an Aggregator server.
• Many zkEVM Provers can connect to the Aggregator server at the same time, providing more proof generation power.
• When called by the Aggregator service to generate a batch proof:
• It calls the Prover component that executes the input data (a batch of EVM transactions), calculates the resulting state, and generates the proof of the calculation based on the PIL polynomials definition and their constrains.
  • The Executor component combines 14 state machines that process the input data to generate the evaluations of the committed polynomials, required to generate the proof. Every state machine generates their computation evidence data, and the more complex calculus demonstrations are delegated to the next state machine.
• The Prover component calls the Stark component to generate a proof of the Executor state machines committed polynomials.
• When called by the Aggregator service to generate an aggregated proof:
  • The Prover component combines the result of 2 previously calculated batch or aggregated proofs, provided by the Aggregator, and generates an aggregated proof.
• When called by the Aggregator service to generate a final proof:
  • The Prover component takes the result of a previously calculated aggregated proof, provided by the Aggregator, and generates a final proof that can be verified.
• The interface of the server of this service is defined by the file aggregator.proto.

Executor service

• It calls the Executor component that executes the input data (a batch of EVM transactions) and calculates the resulting state. The proof is not generated.
• It provides a fast way to check if the proposed batch of transactions is properly built and it fits the amount of work that can be proven in one single batch.
• When called by the Executor service, the Executor component only uses the Main state machine, since the committed polynomials are not required as the proof will not be generated.
• The interface of this service is defined by the file executor.proto.

StateDB service

• It provides an interface to access the state of the system (a Merkle tree) and the database where the state is stored.
• It is used by the executor and the prover, as the single source of state. It can be used to get state details, e.g. account balances.
• The interface of this service is defined by the file statedb.proto.

Setup

Clone repository

$ git clone git@github.com:0xPolygonHermez/zkevm-prover.git
$ cd zkevm-prover
$ git submodule init
$ git submodule update

Compile

The following packages must be installed.

$ sudo apt update && sudo apt install build-essential libbenchmark-dev libomp-dev libgmp-dev nlohmann-json3-dev postgresql libpqxx-dev libpqxx-doc nasm libsecp256k1-dev grpc-proto libsodium-dev libprotobuf-dev libssl-dev cmake libgrpc++-dev protobuf-compiler protobuf-compiler-grpc uuid-dev

To download the files needed to run the prover, you have to execute the following command

$ wget https://de012a78750e59b808d922b39535e862.s3.eu-west-1.amazonaws.com/v1.1.0-rc.1-fork.4.tgz
$ tar -xzvf v1.1.0-rc.1-fork.4.tgz
$ rm -rf config
$ mv v1.1.0-rc.1-fork.4/config .

Run make to compile the project

$ make clean
$ make -j

To run the testvector:

$ ./build/zkProver -c testvectors/config_runFile_BatchProof.json

StateDB service database

To use persistence in the StateDB (Merkle-tree) service you must create the database objects needed by the service. To do this run the shell script:

$ ./tools/statedb/create_db.sh <database> <user> <password>

For example:

$ ./tools/statedb/create_db.sh testdb statedb statedb

Build & run docker

$ sudo docker build -t zkprover .
$ sudo docker run --rm --network host -ti -p 50051:50051 -p 50061:50061 -p 50071:50071 -v $PWD/testvectors:/usr/src/app zkprover input_executor.json

Usage

To execute the Prover you need to provide a config.json file that contains the parameters that allow us to configure the different Prover options. By default, the Prover loads the config.jsonfile located in the testvectorsfolder. The most relevant parameters are commented below with the default value for the provided config.json file:

Parameter	Description
runStateDBServer	Enables StateDB GRPC service, provides SMT (Sparse Merkle Tree) and Database access
runExecutorServer	Enables Executor GRPC service, provides a service to process transaction batches
runAggregatorClient	Enables Aggregator GRPC client, connects to the Aggregator and process its requests
aggregatorClientHost	IP address of the Aggregator server to which the Aggregator client must connect to
runProverServer	Enables Prover GRPC service
runFileProcessBatch	Processes a batch using as input a JSON file defined in the "inputFile" parameter
runFileGenProof	Generates a proof using as input a JSON file defined in the "inputFile" parameter
inputFile	Input JSON file with path relative to the testvectors folder
outputPath	Output path folder to store the result files, with path relative to the testvectors folder
databaseURL	Connection string for the PostgreSQL database used by the StateDB service. If the value is "local" then the service will not use a database and the data will be stored only in memory (no persistence). The PostgreSQL database connection string has the following format: "postgresql://<user>:<password>@<ip>:<port>/<database>". For example: "postgresql://statedb:statedb@127.0.0.1:5432/testdb"
stateDBURL	Connection string for the StateDB service. If the value is "local" then the GRPC StateDB service will not be used and local StateDB client will be used instead. The StateDB service connection string has the following format: "<ip>:<port>". For example: "127.0.0.1:50061"
saveRequestToFile	Saves service received requests to a text file
saveResponseToFile	Saves service returned responses to a text file
saveInputToFile	Saves service received input data to a JSON file
saveOutputToFile	Saves service returned output data to a JSON file

To run a proof test you must perform the following steps:

• Edit the config.json file and set the parameter "runFileGenProof" to "true". The rest of the parameters must be set to "false". Also set the parameter "databaseURL to "local" if you don't want to use a postgreSQL database to run the test
• Indicate in the "inputFile" parameter the file with the input test data. You can find a test file input_executor.json in the testvectors folder
• Run the Prover from the testvectors folder using the command $ ../build/zkProver
• The result files of the proof will be stored in the folder specified in the "outputPath" config parameter