Time boost: a new transaction ordering policy proposal

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This proposal is an improvement on the previous Proof of Work relay scheme, but I think still misses some of the objectives.

As I see it, an MEV mitigation scheme has 3 main objectives:

  1. Move some of the money that searchers are earning, or currently wasting on latency reduction, to the Arbitrum ecosystem.
  2. Eliminate the need for latency races by the searchers, to remove the need for spamming transactions or creating 1000s of connections to the sequencer feed
  3. Achieve the above while damaging the regular customer experience as little as possible

I think this proposal will do a reasonable job of objective 1, although there could be other strategies that will lead to a higher proportion of MEV being paid to the ecosystem

I don’t think this proposal will eliminate the searcher speed races. In the limit of large fees, the time savings a searcher is purchasing (compared to no added latency) will be proportional to gc/F. So when trying to save the last fractions of a millisecond, that will prove very expensive, and hence still worth searchers making many sequencer connections.

On objective 3, one of the main selling points of the Arbitrum ecosystem is its low transaction latency. Even for the regular customer, most transactions will return a response in < 300ms. So to suddenly add an extra 500ms to everyone’s transactions seems like destroying the elegant and efficient system you currently have. Plus messing with the simplicity of FCFS will likely introduce a whole load of new exploits for searchers (blind spamming for sandwich attacks perhaps).

If you want to charge searchers for preferential access, I suggest imposing the delay on the outbound sequencer feed side. That seems much less manipulatable, more controllable, and less impactful on the regular user. For instance, a daily lottery or auction for non-delayed sequencer feed connections. This would be similar to the previous proof of work suggestion, but without the PoW. I’d be happy to work with the team designing a lottery smart contract for ordering of sequencer connections.

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