Plasma Cash - ERC721 Version

Architecture

Client connects to the Child Chain Service, the Root Chain Plasma Contract and the Root Chain Token Contract

Send tx: Client -> Child Chain Service sendtx -> Child Chain server listens to that request and calls child chain sendtransaction, tx gets added to the block

Child Chain ALWAYS listens for events on the RootChain contract and acts on them accordingly

Installation

1. In plasma_cash folder follow the README.md

cd plasma_cash
mkvirtualenv erc721plasma --python=/usr/bin/python3.6
pip install -r requirements.txt

On OSX + Homebrew (may need this)

source /usr/local/bin/virtualenvwrapper.sh

2. In server folder follow the README.md

cd server
npm install

Demos

To run demo, execute the integration test script:

./integration_test.sh

Under demos/ there are various scenarios which can occur. You should have initialized both the smart contracts from the server/ directory, and launched a Plasma Chain instance, as described in the corresponding READMEs.

Demo 1

1. Alice registers and is given coins 1-5
2. Alice deposits Coin 1, Coin 2, Coin 3 in the plasma chain
3. 3 Deposit Blocks have been generated in the child chain, each one having 1 UTXO at slots 0,1,2 repsectively
4. Alice sends a Coin 1 to Bob, adding a transaction to the current block.
5. Operator calls submitBlock, checkpointing the block merkle root which includes the transaction that gives ownership to charlie. At this point, both the child chain and the root chain, have checkpointed alice's transaction at block number 1000.
6. Bob transfers the previous UTXO to Charlie and the operator submits that block as well
7. Charlie tries to exit coin 1, Alice & Bob do not challenge
8. After challenge period passes, charlie should be able to withdraw his coin

Loom SDK integration

To see the integrations run againist the Loom SDK instead of the prototype server

cd server
npm install
cd .. 

cd loom_test
make clean
make deps
make

cd ..
./go_integration_test.sh

Under the loom_test directory there is all the samples in Go, that directly interact with Loom SDK. Usually the SDK is behind our latest research prototypes. As we only move stable Plasma features into the Loom SDK.

For Developers

Using monkeypatched web3.py 4.2.1 version for ganache issues

https://github.com/jordanjambazov/web3.py/commit/a61b382dd5c11de1102779868d377408c7590839 Also ethereum/web3.py#827

Signing locally

http://web3py.readthedocs.io/en/latest/web3.eth.account.html#prepare-message-for-ecrecover-in-solidity

License info

Please note different directories have different licenses. Please see license file in each folder respectively

• server directory -> GPLv2 License
• plasma_cash directory -> GPLv2 License
• loom_test directory -> Loom Public License License