# Native Bridge

KRC-20 includes a built-in **Native Bridge** protocol to support bi-directional bridging of the native asset **KAS** between Layer-1 and KRC-20. Native Bridge is designed with a **minimal trust assumption**: bridged funds are uniformly custodied in a designated Layer-1 covenant-script address (the bridge reserve pool). By leveraging the data verifiability of RTD-Rollup and the global miner submission mechanism, the bridging process becomes traceable, verifiable, and tamper-evident.

### **Bridge-in (KASPA → KRC-20)**

Users transfer KAS on Layer-1 into the bridge reserve pool address. The protocol automatically detects this event and mints an equivalent amount of **bridged KAS** to the user’s address on KRC-20 at a **fixed 1:1 ratio**, completing the cross-layer asset mapping. Because the inbound funds are effectively locked in the Layer-1 bridge reserve pool, KRC-20 KAS reserve remains transparent and auditable.

### **Bridge-out (KRC-20 → KASPA)**

This process reuses the decentralized settlement capabilities of **Atomic Swap**. After a user submits a bridge-out request on KRC-20, Rollup miners write into RTD data the corresponding bid order and settlement information at a **fixed 1:1 price**. Once verified, the protocol authorizes miners — or other eligible executors — to complete the required signatures for the Layer-1 transaction and execute the outbound transfer from the bridge reserve pool address. This design binds bridge-out execution to the verifiable RTD-Rollup mechanism, ensuring that every transfer has explicit on-chain proofs and end-to-end traceability.