Security
Background
Security has always been the biggest critique in the whole cross-chain industry. Butter fully understands the importance of security and that is why we use MAP Protocol as our underlying cross-chain infrastructure.
The core of cross-chain is the alignment of the ledger across different blockchains. Most cross-chain solutions leave this job to third-party external validators such as MPC(Multi-party computing) nodes and trusted Oracles, which is an off-chain trust intermediary similar to traditional banks, this is not a decentralized solution. While light-client relies on the blockchain itself for security and inherits the decentralized nature of blockchains.
About MAP Protocol
MAP Protocol is simply the most secure and comprehensive cross-chain solution. MAP Protocol uses an independent network of self-verified light clients deployed on each blockchain for cross-chain verification, which guarantees blockchain-level security and ensures everything is controlled by codes. We believe the human being is not to be trusted, but code doesn't lie, that's why we are built on the best cross-chain solution that is truly trustless and decentralized. Also, MAP Protocol is adopting ZK technology to reduce cross-chain verfication gas costs. To learn more about MAP Protocol, you can visit the link here.
Light-client and ZK
MAP Protocol uses light client for cross-chain verification. Take PoS blockchain as an example, light client stores the vote weight and public key information of each validator in the committee, and each validator that participates in the current round of consensus requires the signatures of two-thirds of the total voting power of the previous validator committee. If a transaction does not occur in the original blockchain, it wouldn’t have the legitimate validator signature and the transaction will fail since the light-client stores every legitimate validator's public key. Because the light-client stores the public key and voting power of all validators in every committee, it would require attackers to tamper with all the validator information of the original chain from the beginning to the present, which is equivalent to attacking the blockchain itself. This is why light-client’s security depends on the security of the blockchain itself. However, the trade-off is that the light client itself is extremely difficult to implement. Deploying light-client requires a thorough understanding of the underlying design and consensus logic of the blockchain itself. This creates a really high technical barrier. Luckily we have the top scientists and engineers who have been deeply involved in the industry for years. The process of cross-chain transaction verification requires a huge amount of gas fee. ZK packages a batch of cross-chain transactions and verification behaviour directly to ZK nodes for calculation and gives the calculated results to the target light-client and vault with a 300-byte proof. This will dramatically reduce the cross-chain transaction gas fee, even lower than the local blockchain gas fee itself.
The light client and ZK proof itself is not an emerging technology, it is a mature technology that has been highly adopted by the blockchain industry. What we did was to create an innovative architecture that hadn’t existed before to bring these technologies together. Just like Bitcoin and Ethereum. they have used technologies that have been proven in production environments, what they did is an architecture-level innovation.
