Accounts run by code that decides what counts as a valid signature.
The idea: The account is a contract. Instead of a fixed rule ("a valid ECDSA signature from key X"), its own code decides what authorizes a transaction: a passkey, several signers, a spending limit, or a quantum-safe signature. Changing the rule means changing the code, which is the easy path to new cryptography.
Why it matters: The main path to passkeys today and quantum-safe signatures later.
On the map: ERC-4337 / EIP-7702: any signer, the upgrade path to PQ signatures
Accounts controlled by contract code instead of a single fixed key: ERC-4337 accounts[1], and since Pectra (May 2025) ordinary accounts that delegate to code with EIP-7702[2, 3]. Their code decides what counts as a valid signature: multisig, passkeys (P-256), social recovery, or in future post-quantum schemes.
That flexibility is the main upgrade path away from ECDSA. One caveat: an EIP-7702 account's original ECDSA key keeps full control, so a quantum attacker who recovers it could still take over.
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, something people use directly.