- Asset (atomic) transaction
Both parties to the transaction must be atomic, either happening or not happening. There can be no loss or creation of assets out of thin air, and there can be no fraudulent transactions.
2.Verify transactions on another chain
For the confirmation of the transaction, one is to confirm that the transaction has taken place and is connected to the chain, and written into the block ledger; the other is that the transaction has been confirmed by the system in enough blocks, so that the probability of the node doing evil and generating double payments will cause the transaction to be invalid. very low. The blockchain system itself is a relatively closed system and lacks a mechanism to actively obtain external information. Therefore, it is not easy to confirm the transaction status of another chain, which can be said to be one of the core difficulties of cross-chain transactions.
The original chain pair is usually confirmed by consensus, such as notary and relay mode.
The total assets of the two chains remain unchanged and independent and safe
In the scenario of asset swaps, the assets of the two chains have not been substantially exchanged, so this type of situation will not change the total assets of each chain. However, in the scenario of asset transfer, the number of available assets in each chain changes. It can only be achieved if the cross-chain transaction is accurately recorded and the bookkeeping of the two chains is completely synchronized. In other words, it is two chains. The accounting must be atomic, either all at the same time or none at all. In addition, the key to the question is whether the total assets of the two chains can still remain unchanged when a certain chain is restructured.
When two systems interact, they will inevitably affect each other's systems. How to ensure the security of one's own system and the other party's system in the process of cross-chain transactions is a problem worth considering. If the security problem cannot be isolated, that chain will be attacked, which will affect the entire cross-chain network.Cross-chain platform
With reference to the development history of computer networks, independent blockchain networks will eventually embark on an interconnected future. The existing blockchain platforms can be interconnected, and the future blockchain platforms can also be interconnected.Summary
The above five aspects provide some mainstream solutions and solutions in the industry. But not every project involving cross-chain needs to solve all of the above problems, but each takes what it needs.
If you want to realize the cross-chain asset swap function (transfer and use back and forth), solve the first difficulty;
To achieve cross-chain asset transfer (asset lien or mortgage), it is enough to solve the first and second difficulties.
If the system needs to reach a safe and stable state, this needs to consider difficulty three.
If it is necessary to establish a cross-chain platform and a cross-chain agreement, all of the above four difficulties need to be considered.