[Cosmoverse 2023] IBC-Solidity - Programming IBC in Solidity

Transcript

1. IBC-Solidity
   Programming IBC in Solidity
   ・・・
   

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2. Building IBC-bridge in
   non-Cosmos ecosystem
   Enterprise IBC adoption
   IBC-Solidity developer
   

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3. IBC-Solidity Overview
   IBC implementations in Solidity
   - IBC compatibility: v4.0.0
   - Supports EVM-compatible chains such as Ethereum
   Key Features
   - Implementation of ICS (IBC Core/TAO)
   - Implementation of ICS-20 (protobuf encoding)
   - Enable ERC-20 Token Transfer
   

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4. Key Specification
   Integration of Light Client (ICS-02)
   - Implements IClient interface to integrate with IBC-Solidity
   - Examples includes IBFT 2.0, Tendermint Light Client and Mock
   Client
   Internal encoding
   - Currently using solidity-protobuf for Packet encoding unlike
   JSON in specs such as ICS-20
   - Currently, v0.1.0 is required
   

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5. Example: MiniToken 🪙
   IBC-based token transfer between chains
   - Use IBC to create and send packets between blockchains
   - Create a basic token and send tokens to another blockchain
   - Basically, ICS-20 without denomination trace
   https://github.com/hyperledger-labs/yui-docs
   Ledgers used in sample: (MockClient is used for simplicity)
   - Geth
   - Besu (variant of Ethereum client in Java)
   

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6. Contract relationship
   IBCHandler
   (ICS-25)
   IBCChannel
   (ICS-04)
   IBCConnection
   (ICS-03)
   IBCClient
   (ICS-02)
   MiniToken
   (IBCAppBase)
   IBCModule
   (ICS-05)
   IBCPacket
   (ICS-04)
   MiniToken
   PacketData
   bindPort to
   set callbacks
   delegatecall Encode to send
   through IBCHandler
   ibcHandler.bindPort(PortTransfer, MiniToken.address)
   MiniToken App
   IBC-Solidity
   

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7. Packet Structure/Schema for MiniToken
   syntax = "proto3";
   option go_package = "pkg/ibc/app";
   message MiniTokenPacketData {
   // the token amount to be transferred
   uint64 amount = 1;
   // the sender address
   bytes sender = 2;
   // the recipient address on the destination chain
   bytes receiver = 3;
   }
   Generated Packet.sol:
   https://github.com/hyperledger-labs/yui-docs/blob/main/contracts/minitoken/solidi
   ty/contracts/lib/Packet.sol
   

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8. Key Functions for MiniToken: Send data
   function sendTransfer(
   uint64 amount, address receiver,
   string calldata sourcePort,
   string calldata sourceChannel,
   uint64 timeoutHeight
   ) external {
   require(_burn(msg.sender, amount), "MiniToken: failed to burn");
   _sendPacket(
   MiniTokenPacketData.Data({
   amount: amount,
   sender: abi.encodePacked(msg.sender),
   receiver: abi.encodePacked(receiver)
   }),
   sourcePort, sourceChannel, timeoutHeight
   );
   emit SendTransfer(
   msg.sender, receiver, sourcePort, sourceChannel, timeoutHeight, amount
   );
   }
   

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9. Key Functions for MiniToken: Send data (Contd.)
   function _sendPacket(
   MiniTokenPacketData.Data memory data,
   string memory sourcePort,
   string memory sourceChannel,
   uint64 timeoutHeight
   ) internal virtual {
   ibcHandler.sendPacket(
   sourcePort,
   sourceChannel,
   Height.Data({
   revision_number: 0,
   revision_height: timeoutHeight
   }),
   0,
   MiniTokenPacketData.encode(data)
   );
   }
   interface IIBCPacket {
   function sendPacket(
   string calldata sourcePort,
   string calldata sourceChannel,
   Height.Data calldata timeoutHeight,
   uint64 timeoutTimestamp,
   bytes calldata data
   ) external returns (uint64);
   

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10. Key Functions for MiniToken: Callbacks
    function onRecvPacket(Packet.Data calldata packet, address /*relayer*/)
    external virtual override
    onlyIBC
    returns (bytes memory acknowledgement)
    {
    MiniTokenPacketData.Data memory data = MiniTokenPacketData.decode(
    packet.data
    );
    return
    _newAcknowledgement(_mint(data.receiver.toAddress(), data.amount));
    }
    function onAcknowledgementPacket(
    Packet.Data calldata packet,
    bytes calldata acknowledgement, address /*relayer*/
    ) external virtual override onlyIBC {
    if (!_isSuccessAcknowledgement(acknowledgement)) {
    _refundTokens(MiniTokenPacketData.decode(packet.data));
    }
    }
    

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11. MiniToken: Scenario
    Alice@ibc0
    (Besu)
    Bob@ibc1
    (Geth)
    1. Mint 100 token
    2. Send 50 token
    3. Return 25 token
    

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12. Demo
    https://asciinema.org/a/611589
    

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13. $ truffle console --network=ibc0
    truffle(ibc0)> MiniToken.deployed().then((instance) => instance.balanceOf(accounts[1]))
    BN { negative: 0, words: [ 0, <1 empty item> ], length: 1, red: null }
    truffle(ibc0)> MiniToken.deployed().then((instance) => instance.balanceOf(accounts[1]))
    BN {
    negative: 0,
    words: [ 100, <1 empty item> ],
    length: 1,
    red: null
    }
    truffle(ibc0)> await MiniToken.deployed().then(instance => instance.mint(accounts[1], 100));
    {
    tx: '0xce...',
    receipt: {
    ...
    },
    logs: [
    {
    ...
    event: 'Mint',
    args: [Result]
    }
    ]
    }
    

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14. truffle(ibc0)> await MiniToken.deployed().then(instance =>
    instance.sendTransfer(50, accounts[2], "transfer", "channel-0", 1500, {from:
    accounts[1]}));
    {
    tx: '0x011...',
    receipt: {
    ...
    },
    logs: [
    {
    ...
    event: 'Burn',
    args: [Result]
    },
    {
    ...
    event: 'SendTransfer',
    args: [Result]
    }
    ]
    }
    

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15. truffle(ibc1)> MiniToken.deployed().then((instance) => instance.balanceOf(accounts[2]))
    BN { negative: 0, words: [ 50, <1 empty item> ], length: 1, red: null }
    truffle(ibc1)> await MiniToken.deployed().then(instance => instance.sendTransfer(25,
    accounts[1], "transfer", "channel-0", 1500, {from: accounts[2]}));
    {
    tx: '0xd7f...',
    receipt: {
    ...
    },
    logs: [
    {
    ...
    event: 'Burn',
    args: [Result]
    },
    {
    ...
    event: 'SendTransfer',
    args: [Result]
    }
    ]
    }
    truffle(ibc1)> MiniToken.deployed().then((instance) => instance.balanceOf(accounts[2]))
    BN { negative: 0, words: [ 25, <1 empty item> ], length: 1, red: null }
    

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16. Related Projects
    YUI-Relayer: https://github.com/hyperledger-labs/yui-relayer
    - Modular architecture to support multiple chains (forked go-relayer)
    - Abstraction of “Chain” and “Prover”
    - Supports non-instant finality chains such as Ethereum
    Cosmos Ethereum LCP:
    https://github.com/datachainlab/cosmos-ethereum-ibc-lcp
    - Presented in keynote from 15:50
    [IBC Gets Ready to Land on Ethereum]
    - PingPong between Cosmos and Ethereum with full-fledged light clients
    

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17. Roadmap
    - Already on Testnet (Sepolia)
    - Audit -> December
    - Mainnet 🚀 -> Early 2024
    - Bridge to Noble -> 2024
    Other teams also have plans 💝
    

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18. Key Issues
    - ICS-20: Use JSON for packet data serialization
    - ICS-30: Middleware support
    You can refer to issues:
    https://github.com/hyperledger-labs/yui-ibc-solidity
    

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19. Contact / Further Information
    Toki Finance
    https://linktr.ee/tokifinance
    Datachain
    https://www.datachain.jp/
    

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