# Fundamental Logic of Bridge

### 1.How to move Bitcoin asset to Layer2 (BEVM)?

Step 1:Implement the original Bitcoin code on the chain. Bitcoin light node source code.

Step2:Listen for the relevant cross-chain to Layer 2 address accounts, relayer performs on-chain light node and Bitcoin full node code and Synchronization of data.



### 2.How to move Layer2 (BEVM) asset to Bitcoin?

The Taproot threshold signature algorithm combines the privacy-distributed threshold signature implemented by the Signal protocol.&#x20;

Multiple Layer 2 verification nodes generate aggregate signature contracts, and then each verification node performs encrypted communication interoperable aggregate signature contracts through the distributed privacy algorithm of the Signal protocol to realize the return of BTC assets from Layer 2 to the Bitcoin mainnet.
