  MEV attacks have been an omnipresent evil in the blockchain world, an
implicit tax that uninformed users pay for using the service. The problem
arises from the miners' ability to reorder and insert arbitrary transactions in
the blocks they mine. This paper proposes a 2-phased transaction protocol to
eliminate MEV attacks. The user requests an interaction token from the on-chain
counter-party. This token serves as a blind preemption for the counter-party
and prevents the reordering of transactions at lower levels in the blockchain
framework. We prove the correctness of the CoMMA protocol and demonstrate its
efficacy against MEV attacks.
