Etherspot explains: EIP-7851
EIP-7702 introduced delegated EOAs, allowing regular Ethereum accounts to adopt smart account functionality.
EIP-7851 builds on that idea by proposing a protocol-level mechanism that allows delegated EOAs to disable their original ECDSA signing authority.
The goal is simple: reduce the risks of keeping the original EOA key active after delegation, especially in multi-chain setups where the same ECDSA key may control accounts across multiple EVM networks.
The proposal is evolving through ongoing Ethereum research and core-dev discussions. The latest design update introduces SETSELFDELEGATE(delegate_address), a self-only opcode that allows delegated wallet code to write the 0xef0101 || delegate_address marker.
This permanently disables residual ECDSA authority while still allowing wallet code to update the delegate in ECDSA-disabled mode.
One of the key ideas behind the design is that delegated wallet code, not the original EOA key, should control when the transition is finalized.
At a broader level, EIP-7851 reflects a growing push toward making delegated EOAs behave less like partially upgraded EOAs and more like fully transitioned programmable accounts.