The co-founder of Ethereum identifies "fundamental security limits of bridges" as the main cause for his rejection.
Vitalik Buterin, the co-founder of Ethereum (ETH), expressed severe security issues about cross-chain bridges in the blockchain ecosystem in a Reddit post on Friday. Buterin says that keeping native assets straight on the chain (Ethereum on Ethereum, Solana on Solana, etc.) gives considerable protection against 51% attacks. Though if hackers can censor or reversal transactions, they are not able to suggest blocks that will strip away one's crypto.
The Ethereum application is also subject to regulation. For instance, if hackers execute a 51% attack (managing 51% of all circulating ETH supply) whereas an investor trades 100 ETH for 320,000 DAI stablecoin, the final result remains constant, i.e., the investor continuously receives either 100 ETH or 320,000 DAI.
Buterin went on to say that cross-chain bridges do not have the same degree of security.
In the instance, he cited, if an attacker transferred their own ETH onto a Solana (SOL) bridge to acquire Solana-wrapped Ether (WETH), then retracted the transaction on the Ethereum side as quickly as possible as the Solana side approved it, other users whose tokens are trapped in the SOL-WETH contract would undergo severe losses because the wrapped tokens are no longer supported by the original on a ratio of 1:1.
Buterin went on to explain how the security flaw could worsen the issue if more links are added to a cross-chain network. Because of the high extent of interconnection and intersecting variables in a theoretical network of 100 chains, a 51% attack on one chain, particularly a small-cap chain, can induce system-wide spread.
A 51 % attack vector against the Ethereum network can cost as much as $1.78 million per hour, as per Crypto 51. For blockchains like Bitcoin Cash, though, the cost reduces to as low as $13,846 per hour.