Relay System for BTP 2.0

Introduction

This is a reference relay implementation for BTP 2.0 protocol.

Target chains

• ICON (BTP Block)
• Hardhat (EVM-compatible chain)

Terminologies

Word	Description
BTP	Blockchain Transmission Protocol, see ICON BTP Standard.
BTP Message	A verified message which is delivered by the relay
Service Message	A payload in a BTP Message
Relay Message	A message including BTP Messages with proofs for that, and other block update messages.
Network Address	A string to identify blockchain network ex) 0x1.icon
BTP Address	A string of URL for locating an account of the blockchain network ex) btp://0x1.icon/cx87ed9048b594b95199f326fc76e76a9d33dd665b

Components

• BTP Message Center (BMC) - smart contract

  • Receive BTP messages through transactions.
  • Send BTP messages through events.

• BTP Message Verifier (BMV) - smart contract

  • Update blockchain verification information
  • Verify delivered BTP message and decode it

• BTP Service Handler (BSH) - smart contract

  • Handle service messages related to the service.
  • Send service messages through the BMC

• BTP Message Relay (BMR) - external software (implemented by this repository)

  • Monitor BTP events
  • Gather proofs for the events
  • Send BTP Relay Message

Getting Started

1. git clone https://github.com/icon-project/btp2.git --recurse-submodules
2. cd btp2
3. make relay

E2E Testing Demo

• Follow the instruction in End-to-End Testing Demo folder.

Repository Structure

References

• ICON BTP Standard