cosmos-sdk/docs/spec/ibc/ibc.md

# IBC Specification

IBC(Inter-Blockchain Communication) protocol is used by multiple zones on Cosmos. Using IBC, the zones can send coins or arbitrary data to other zones.

## MVP Specifications

### [MVP1](./mvp1.md)

MVP1 will contain the basic functionalities, including packet generation and packet receivement. There will be no security check for incoming packets.

### [MVP2](./mvp2.md)

IBC module will be more modular in MVP2. Indivisual modules can register custom handlers to IBC module.

### [MVP3](./mvp3.md)

Light client verification is added to verify the message from the other chain. Registering chains with their ROT(Root Of Trust) is needed.

### [MVP4](./mvp4.md)

ACK verification and messaging queue is implemented to make it failsafe. Modules will register callback to handle failure when they register handlers.