Since each blockchain is an island, asset transfer can currently only be achieved indirectly by means of exchange. This makes the term “cross-chain” somewhat of a misnomer. Assets do not “cross” chains. 

For example, suppose you want to transfer BTC to Ethereum. BTC has a shadow token, tBTC, on Ethereum. An intermediary provides a pool of BTC on the Bitcoin blockchain and a pool of tBTC on the Ethereum blockchain. To “transfer” BTC to Ethereum, you “lock” the BTC into the intermediary’s pool on the Bitcoin blockchain and receive a corresponding amount of tBTC from the intermediary’s pool on the Ethereum blockchain. The intermediary uses a series of consensus to ensure that the amount of tBTC is the same as the amount of locked positions on BTC, but this still requires you to trust the correct behavior of the intermediary. 

Every blockchain is an isolated island 

Cross-chain 

Multi-chain 

Multievent

Existing solutions 

Introduction

Blockchain, cross-chain, and multi-chain 

I/O primitives 

Overview of MEP 

A new approach to multi-chain message transmission

General design 

Description of each module 

The economic model

Community shared governance 

System design of MEP

Security of MEP

MEP Orderbook 

MEP Automated Exchange

MEP Wallet 

MEP ERC20 Contracts

Multi-chain dApps 

Conclusion 