Most blockchains have a common problem where blocks can be front run as the block producers/validators have full control on the ordering of transactions.
If blocks can be front run, it is unlikely a large DEX (if non AMM - automated market maker), could work as it would be impossible to determine which order came first fairly, to execute trades. Don’t event mention HFT.
Tezos has so much potential as a functional programming based protocol etc with michelson, to take lead in DEFI, but I think this needs to be solved.
Hedera hashgraph does have a cool solution for this as it takes a medium timestamp of all gossip validators. I have not seen a similar solution for eth.
First things first, it’s not “front running” unless there is some sort of fiduciary duty. Now that this is out of the way, there are different ways to address the topic.
One solution is commit / reveal, and require that the commitment be time-lock encrypted to make sure they can be decrypted. A faster solution (but requiring a bit more trust) involves encrypting orders with a threshold scheme and having them decrypted by a subset of the key holders. You could have protocol level support for this, for example by calling on the endorsers to generate a decryption key, but liveness issues have to be taken into consideration.
