[Roadmap] Account abstraction

We have been talking about account abstraction ever since early 2016, see the original EIP-86: https://github.com/ethereum/EIPs/issues/86

Now, we finally have EIP-8141 ( https://eips.ethereum.org/EIPS/eip-8141 ), an omnibus that wraps up and solves every remaining problem that AA was intended to address (plus more). Let's talk again about what it does.

The concept, "Frame Transactions", is about as simple as you can get while still being highly general purpose. A transaction is N calls, which can read each other's calldata, and which have the ability to authorize a sender and authorize a gas payer. At the protocol layer, that's it.

Now, let's see how to use it.

First, a "normal transaction from a normal account" (eg. a multisig, or an account with changeable keys, or with a quantum-resistant signature scheme). This would have two frames:

• Validation (check the signature, and return using the ACCEPT opcode with flags set to signal approval of sender and of gas payment)
• Execution

You could have multiple execution frames, atomic operations (eg. approve then spend) become trivial now.

If the account does not exist yet, then you prepend another frame, "Deployment", which calls a proxy to create the contract (EIP-7997 https://ethereum-magicians.org/t/eip-7997-deterministic-factory-predeploy/24998 is good for this, as it would also let the contract address reliably be consistent across chains).

Now, suppose you want to pay gas in RAI. You use a paymaster contract, which is a special-purpose onchain DEX that provides the ETH in real time. The tx frames are:

• Deployment [if needed]
• Validation (ACCEPT approves sender only, not gas payment)
• Paymaster validation (paymaster checks that the immediate next op sends enough RAI to the paymaster and that the final op exists)
• Send RAI to the paymaster
• Execution [can be multiple]
• Paymaster refunds unused RAI, and converts to ETH

Basically the same thing that is done in existing sponsored transactions mechanisms, but with no intermediaries required (!!!!). Intermediary minimization is a core principle of non-ugly cypherpunk ethereum: maximize what you can do even if all the world's infrastructure except the ethereum chain itself goes down.

Now, privacy protocols. Two strategies here. First, we can have a paymaster contract, which checks for a valid ZK-SNARK and pays for gas if it sees one. Second, we could add 2D nonces (see https://docs.erc4337.io/core-standards/rip-7712.html ), which allow an individual account to function as a privacy protocol, and receive txs in parallel from many users.

Basically, the mechanism is extremely flexible, and solves for all the use cases. But is it safe? At the onchain level, yes, obviously so: a tx is only valid to include if it contains a validation frame that returns ACCEPT with the flag to pay gas. The more challenging question is at the mempool level.

If a tx contains a first frame which calls into 10000 accounts and rejects if any of them have different values, this cannot be broadcasted safely. But all of the examples above can. There is a similar notion here to "standard transactions" in bitcoin, where the chain itself only enforces a very limited set of rules, but there are more rules at the mempool layer.

There are specific rulesets (eg. "validation frame must come before execution frames, and cannot call out to outside contracts") that are known to be safe, but are limited. For paymasters, there has been deep thought about a staking mechanism to limit DoS attacks in a very general-purpose way. Realistically, when 8141 is rolled out, the mempool rules will be very conservative, and there will be a second optional more aggressive mempool. The former will expand over time.

For privacy protocol users, this means that we can completely remove "public broadcasters" that are the source of massive UX pain in railgun/PP/TC, and replace them with a general-purpose public mempool.

For quantum-resistant signatures, we also have to solve one more problem: efficiency. Here's are posts about the ideas we have for that: https://firefly.social/post/lens/1gfeyxjzsajqk845t3h https://firefly.social/post/x/2027405623189803453

AA is also highly complementary with FOCIL: FOCIL ensures rapid inclusion guarantees for transactions, and AA ensures that all of the more complex operations people want to make actually can be made directly as first-class transactions.

Another interesting topic is EOA compatibility in 8141. This is being discussed, in principle it is possible, so all accounts incl existing ones can be put into the same framework and gain the ability to do batch operations, transaction sponsorship, etc, all as first-class transactions that fully benefit from FOCIL.

Finally, after over a decade of research and refinement of these techniques, this all looks possible to make happen within a year (Hegota fork).