Guy1m0/piechain_frontend

PIEChain

We develop a general cross-chain communication framework that uses the Kafka protocol for secure interaction.

Entities

• The Kafka network provider, who maintains the Kafka network.
• Developers, who develops cross-chain services (CC-SVCs) using an event- driven approach.
• End users, who deploy smart contracts and use the CC-SVCs for cross- chain operations.

Setup

Kafka

Start Kafka with docker-compose.

cd kafka
docker-compose up -d

# to stop after experiments
docker-compose down

Fabric

Install Hyperledger Fabric.

cd fabric
./install.sh

Ethereum

Install go-ethereum and quorum.

cd ethereum
sudo ./install.sh

Usage

Register event handlers for different services.

ccsvc, err = cclib.NewEventService(
	[]string{"zoolkeeper_nodes"},
	"service_name",
)
check(err)
// register event handlers
ccsvc.Register("event_1", handleEvent1) 
ccsvc.Register("event_2", handleEvent2)
err = ccsvc.Start() // start service
check(err)

Publish events with corresponding payloads

b, _ := json.Marshal(Event1Body{
	Hash: hash,
	// ...
})
ccsvc.Publish("event_1", b)

Example Applications

Flash Loan

Demo

You can run the cross-chain flash loan demo by the following steps.

1. Run Fabric.

cd fabric-samples/test-network
./network.sh up createChannel

# to stop fabric after experiment
./network.sh down

2. Run ethereum.

cd ethereum/poa
./remove.sh
./init.sh
./start.sh

# to stop ethereum after experiment
./stop.sh

NOTE: Check log.txt file to ensure that ethereum is running.

3. Deploy contracts fabric_erc20 and lender on fabric.

cd fabric-samples/test-network
./network.sh deployCC -ccn token1 -ccp ../../contracts/fabric_erc20/chaincode/ -ccl go
./network.sh deployCC -ccn lender -ccp ../../contracts/fabric_lender/chaincode/ -ccl go

4. Run cclender and ccarbit in two different terminals. They are the cross-chain exchange services responsible for relaying messages between two blockchains.

cd examples/flashloan/cclender
go build .
./cclender

cd examples/flashloan/ccarbit
go build .
./ccarbit

5. Setup tokens and amm exchanges using cli

cd examples/flashloan/cli
go build .
# Deploy tokens and amm contracts and allocate initial coins.
./cli -c setup

6. Setup flashloan contract arbitrage on ethereum.

cd examples/flashloan/arbitrageur
go build .
# Deploy arbitrage contract on ethereum.
# Setup both lender and arbitrage contract and generate a signature.
./arbitrageur -c setup

You can check the results in flash_loan.json and commit_vote.json in the flashloan folder.

7. Register the new flashloan to the cc services.

# from arbitrageur directory
./arbitrageur -c register

8. Sign Commit Vote by lender.

cd examples/flashloan/lender
go build .
./lender -c sign

9. Initialize flash-loan with commit vote by lender.

# from lender directory
./lender -c initialize

After this step, cross-chain services will detect lender initialization on fabric and transfer loan to arbitrage contract on ethereum.

10. Execute arbitrage by arbitrageur.

./arbitrageur -c execute

If execute is successful, the arbitrage contract will transfer loan + intrest to the cross-chain exchange and the cross-chain services will transfer loan + intrest to the lender. if execute is failed, the lender will still get refund of initial loan on fabric.

You can check the token balances on both blockchains using this command.

# from cli directory
./cli -c display

Auction with three blockchains

Demo

You can run the auction example by the following steps.

1. Run Fabric.

cd fabric-samples/test-network
./network.sh up createChannel

2. Run Ethereum POA.

cd ethereum/poa
./remove.sh
./init.sh
./start.sh

3. Run Quorum Raft.

cd ethereum/raft
./remove.sh
./init.sh
./start.sh

4. Deploy fabric_asset on fabric.

./network.sh deployCC -ccn asset -ccp ../../contracts/fabric_asset/chaincode -ccl go

5. Run relayer crosschain service.

cd examples/auction/relayer
go build .
./relayer

6. Run signer crosschain services.

cd examples/auction/signer
go build .

# on different terminals
./signer -t -p ethereum -eth localhost:8545 -key ../../keys/key1 -id 1
./signer -p ethereum -eth localhost:8545 -key ../../keys/key2 -id 2
./signer -p quorum -eth localhost:8546 -key ../../keys/key1 -id 1
./signer -p quorum -eth localhost:8546 -key ../../keys/key2 -id 2

7. Run the scenario script.

cd examples/auction/scenario
go run .

The scenario script will do the following steps.

1. Add a new asset on the fabric asset contract.
2. Deploy auction contracts on ethereum and quorum.
3. Create a new auction for this asset on on fabric.
4. Bid correspondingly on both ethereum and quorum.
5. End auction on fabric and print out the winner info and final asset owner on fabric.

Auction with Ethereum POW

Demo

You can run the auction example by the following steps.

1. Run Fabric.

cd fabric-samples/test-network
./network.sh up createChannel

2. Run Ethereum POW.

cd ethereum/pow
./remove.sh
./init.sh
./start.sh

3. Deploy fabric_asset_pow on fabric.

./network.sh deployCC -ccn asset -ccp ../../contracts/fabric_asset_pow/chaincode -ccl go

4. Run relayer crosschain service.

cd examples/auction_pow/relayer
go build .
./relayer

5. Run end_listener crosschain services.

cd examples/auction_pow/end_listener
go build .
./end_listener

6. Run the scenario script.

cd examples/auction_pow/scenario
go run .

The scenario script will do the following steps.

1. Add a new asset on the fabric asset contract.
2. Deploy auction contract on ethereum.
3. Create a new auction for this asset on on fabric.
4. Bid on both ethereum.
5. End auction on ethereum.
6. end_listener will listen to ethereum auction ending and will publish on_end_auction event with POW headers and merkle proof for auction wiiner.
7. On receiving on_end_auction event, relayer will end auction on fabric.