Why use the spv scheme in Orbiter Finance

The Bitcoin Whitepaper introduced SPV. The security model of SPV establishes a trusted roothash on the chain that executes the SPV and verifies it, so that the entire model can be both safe and economical. People realize that using SPV can achieve cross-chain. However, this is not perfect.

When addressing cross-chain issues with SPV, the generation of roothash requires additional governance costs because the consensus between chains is established off-chain. It reduces the safety and economy of the cross-chain. How to get trusted roothash becomes a new problem.

Rollups successfully solved the problem of cross-chain security. The security of roothash generated by rollup technology is consistent with that of L1 because its consensus is based on L1, so the SPV project deployed on L1 is naturally available.

The cross-chain security problem has been solved. However, due to the lack of timeliness of roothash verification, high gas fees and time costs will be incurred when Rollups withdraw money from L1 and transfer money between rollups. Thus its economics is still not guaranteed.

Therefore, reducing time and interactive gas fees when crossing rollups becomes a new proposition. So Orbiter was created to solve this problem. The original intention was to use the SPV safety model designed for Rollups to reduce the cross-rollups withdrawal time and gas fees.

At the same time, Orbiter’s unique design enables the entire project to have long-term compatibility. It can grow together with rollups and become an essential infrastructure in the rollup ecosystem. In addition to addressing the general problems of rollups interaction, Orbiter also has the following features :

* Less reliance on smart contracts;
* Support developers to customize cross-rollup combinations;
* Reasonable rollups’ liquidity economic system;