Buterin: The future will be "multi-chain" rather than "cross-chain", and cross-chain bridges have basic security restrictions

On January 8, Ethereum co-founder Vitalik Buterin retweeted a link to a Reddit post on Twitter and commented that "the future will be 'multi-chain' rather than 'cross-chain'.

Buterin believes that "there are fundamental security limitations in cross-chain bridges" and further explained that he disagrees with the idea that all security mechanisms will fail when the blockchain suffers a 51% attack, which aims to control more than 50% of the Network mining power to manipulate the integrity of transactions registered in the blockchain.

Buterin stated that in the case of a 51% attack, an attacker cannot propose a block that takes someone's ETH, because such a block would violate the consensus rules and thus be rejected by the network. In other words, he believes that even if 99% of the computing power is used to illegally take ETH from another wallet, the node will simply follow the remaining 1% of the chain because it is the only block set that follows the rules of the protocol, so "Honest" blocks will always maintain state consistency.

Buterin pointed out that the problem arises when users connect assets from their native blockchain to a non-native blockchain, stating: “If Ethereum gets a 51% attack and recovers, Arbitrum and Optimism recover as well, So even if Ethereum is 51% attacked, a 'cross-rollup' application that maintains state on Arbitrum and Optimism is guaranteed to be consistent. If Ethereum is not 51% attacked, then a 51% attack cannot attack Arbitrum and Optimism respectively. "

Buterin concluded by saying that he does not expect these problems to arise immediately, but as the number of cryptocurrencies held in cross-chain bridges increases, so does the incentive to attack them.

Buterin: The future will be "multi-chain" rather than "cross-chain", and cross-chain bridges have basic security restrictions