I have research EOS inter blockchain communication for a week off and on. Now write down my research result, and I will constantly update related content.
1, inter blockchain main purpose is to solve the problem one block chain's token use in another block chain.
2, EOS realized inter blockchain communication by one block chain prove other block chain's action use merkle tree. following is the detailed description .
First, In every EOS block header,there are three merkle root. two of them are block information and action information.
we can prove one action exist in other block chain by block information merkle tree, also can prove validity by action merkle tree.