Planned: a simpler, more proof-friendly way to store Ethereum's state.
Why it matters: Smaller proofs for light clients and zero-knowledge provers.
On the map: replaces the Keccak Merkle- Patricia trie, hash TBD: BLAKE3, Keccak or Poseidon2
Map note, rests on: collision resistance of the chosen hash
EIP-7864 would replace the Merkle-Patricia tries with a single binary tree[1], targeted at strawmap fork I*[2]. Binary trees give much smaller proofs, which matters for stateless clients and for proving execution in ZK.
The hash function is not decided: the draft uses BLAKE3 for experimentation, with Keccak and Poseidon2 as candidates. Security rests on that hash's collision resistance.
If any of these breaks, this breaks too.
If this breaks, these break with it.
Nothing on the map depends on it: it is an end point of the roadmap.