EIP-4788 is an Ethereum Improvement Proposal introducing a mechanism for the execution layer of Ethereum mainnet to access the beacon roots of the consensus layer. This access is provided through a regular smart contract which acts as a temporary database.^[1]

Overview

EIP-4788 introduces an unconventional change to the Ethereum Virtual Machine (EVM) by embedding the parent beacon block root directly into each execution block. The beacon block root-containing contract will allow any mainnet-deployed smart contract to query and gain information about Ethereum’s consensus state in a trust-minimized manner. A ring buffer is used to ensure that only a limited number of consensus state roots are stored, to avoid the contract’s state growing indefinitely. The EVM is the engine that powers smart contracts on Ethereum. Beacon chain, on the other hand, is the backbone of Ethereum's Proof-of-Stake (PoS) consensus mechanism, responsible for validating transactions and securing the network. The beacon block root acts as a cryptographic fingerprint of the latest state on the beacon chain.^[1][3][4]

Before EIP-4788, smart contracts lacked a built-in mechanism to access the beacon chain's state. This posed a challenge for applications that required verification of events occurring on the consensus layer. EIP-4788 solves this by including the beacon block root within each block on the execution layer. Smart contracts can then cryptographically validate the root against a known beacon chain to ensure they are operating on the latest consensus state.^[1]

EIP-4788 transforms the Ethereum Virtual Machine (EVM) into an oracle, providing trust-minimized access to Ethereum’s consensus state. And this enhancement commits the hash tree root of each parent beacon block in the execution block’s header. These roots are stored in a smart contract on Ethereum mainnet, utilizing a ring buffer to manage storage efficiently. The parent beacon block roots enable any Ethereum contract to access recent consensus layer state in a trust-minimized way.^[2]

EIP-4788 eliminates the need for trusted oracle solutions in gaining information about Ethereum’s consensus state. Once this EIP is merged, smart contracts and protocols deployed on Ethereum mainnet will no longer require a trusted oracle solution to gain information about Ethereum’s consensus state. Importantly, this consensus state information can be “unpacked”, and used to determine the status and balance of all Ethereum validators. Liquid staking pools, such as Lido and Rocket Pool, and re-staking applications like EigenLayer, stand to benefit. This upgrade enhances the security, trustworthiness, and efficiency of these applications by providing cryptographically verifiable consensus state information.^[2][3]

EIP-4788 is a fundamental component of the Dencun upgrade, a significant step forward for Ethereum. Dencun, which translates to "fragment" in Chinese, refers to a set of EIPs aimed at enhancing Ethereum's scalability and efficiency. EIP-4788 works in conjunction with other EIPs within Dencun, such as EIP-4844 (which introduces data sharding), to create a more robust and scalable Ethereum network.

Authors

• Alex Stokes
• Ansgar Dietrichs
• Danny Ryan
• Martin Holst Swende
• lightclient