Vitalik Buterin Is Pessimistic About Chain Bridges
Vitalik Buterin, co-founder of Ethereum and a developer, shared a link to a Reddit article today in which he addressed his conviction in a multi-chain future but raised reservations about cross-chain ecosystems.
Buterin mentioned the “basic security limitations of bridges” as a primary reason for his opposition to a cross-chain ecosystem in his thesis.
Buterin said in his explanation that he disagrees with the notion that all security procedures fail if and when a blockchain is subjected to a 51 percent assault. A 51 percent attack aims to alter the integrity of blockchain transactions by gaining control of more than 50% of the network’s mining hash rate or processing power.
Buterin said that in the event of a 51 percent assault, the attacker/s cannot submit a block that deprives someone of their ETH, since such a block would break the network’s consensus rules and hence be rejected. In other words, he maintained, even if 99 percent of hashpower was dedicated to fraudulently stealing ETH from another wallet, nodes would simply follow the chain of the remaining 1% since it is the only set of blocks that adheres to protocol regulations. Thus, Buterin said, the “honest” blocks would maintain the state’s consistency.
Buterin stated that the issue arises when users transfer assets from their native blockchains to non-native blockchains. If the native blockchain is subjected to a 51 percent assault, and the bridge transaction is reverted, those assets may be left “orphaned” or “siloed” on the non-native (destination) blockchain, leaving the user with a contract that is no longer completely supported by the original blockchain.
Additionally, Buterin explained that the same logic holds true for any Layer 2 established on the Ethereum main chain. He wrote the following in this regard:
“If Ethereum is 51 percent attacked and reverts, Arbitrum and Optimism will also revert, guaranteeing that “cross-rollup” apps that maintain state on Arbitrum and Optimism will stay consistent even if Ethereum is 51 percent attacked. And if Ethereum is not attacked at 51%, there is no way to attack Arbitrum and Optimism independently at 51%.”
The author continues by stating that by using decentralised applications that are interconnected across several chains, we may experience a “contagion effect” in which a 51 percent assault can damage a whole ecosystem. Vitalik emphasises that he supports zones of sovereignty in which numerous native Layer 1 apps communicate directly with one another rather than with other blockchain environments.
Buterin finished by stating that although he did not anticipate these issues arising immediately, he believes that as the number of bitcoin kept in bridges increases, the motivation to attack them would increase as well.