Ethereum researcher and data analyst Tony Warstetter said that the “block builders” in MEV-Boost purposefully exclude transactions associated with sanctioned crypto addresses.

Toni Wahrstätter stated that Ethereum users can now be censored at different levels of the stack. In particular, “data block builders” hosted in MEV-Boost, a middleware supported by almost all Ethereum validators, can create exceptional blocks that do not contain certain transactions. For example, towards users blacklisted by the Treasury Department’s Office of Foreign Assets Control (OFAC).

In turn, Ethereum relays can refuse to relay them, and validators can create local blocks that strictly exclude certain objects or only connect to relays with mandatory censorship.

Warstetter noted that at the initial stage, everyone in the Ethereum community believed that OFAC’s attempts to introduce censorship would fail due to the fact that the ecosystem would be immune to it due to its repeatedly declared decentralized design. However, this did not happen, and about 72% of Ethereum blockchain blocks are now considered “censored”, up from about 25% in November 2022.

“Block creators have the right to individually decide which transactions and in what order they place in blocks, and which they want to censor. This means that block creators now decide on the content of the blockchain. This is a marked departure from the original vision of Ethereum as a network where “code is law,” where software replaces middlemen, and decentralized networks can operate without restrictions from centralized companies and governments,” Warstetter said.

According to him, of the five largest block producers, only one, Titan Builder, explicitly states that it does not “filter” transactions. Thus, if Titan decides to censor transactions tomorrow, then the concentration of censorship in the Ethereum blockchain will exceed 90%, the crypto expert believes.

Earlier, at the Devconnect event in Turkey, Ethereum co-founder Vitalik Buterin presented a new strategy aimed at improving the staking mechanism and performance of the Ethereum blockchain.