Trust Assumptions

Avalanche Warp Messaging uses a trick: The trusted third party is the validator set of the source L1. We are already trusting them, or else we wouldn't communicate with that L1.

The only thing that needs to be ensured is that there is always an AWM Relayer doing the signature aggregation and delivery of the warp message. Since it will have to pay gas on the destination chain, the sender needs to make sure it has enough incentives to do so. Either those incentives come from the sender itself, or from the receiving L1 if it has an inherent interest to onboard users to its chain. You will learn how users can incentivize AWM Relayers with ERC20 tokens with Interchain Messaging in following chapters.

Generally, if there were no relayer available, anyone could run a AWM Relayer and deliver their own messages.