Security of MEP

The goal of MEP is an infrastructure service for a multi-chain ecosystem. In building infrastruc ture, guaranteeing the validity and correctness of the query results and signatures is of paramount importance. MEP has the following measures to ensure security: 

• We use a double filtering mechanism similar to ChainLink. Each MEP node will collect messages from multiple nodes of an underlying blockchain. These messages must all agree. Then all the MEP nodes must agree. In other words, MEP nodes must reach consensus both within and between themselves. 

• In order to prevent MEP nodes from reading overlapping underlying blockchain nodes, we require the MEP nodes to provide a list of the underlying nodes they will be fetching data from at the time of consensus to ensure the decentralization of the data sources. 

• While third-party oracles like ChainLink mainly use off-chain data, MEP uses on-chain data, which is integrated, consensual, formatted and can provide proofs. When we provide the queried data, we can also provide a Merkel proof at the same time for users to judge. Even for some special chains, we can run the light node of the chain inside the MEP node, which can guarantee the validity of the data. 

• We design our economic model using DPoS consensus to handle the problem of some nodes being evil and to reward the majority of decent nodes. 

• For the signature service, we use a threshold signature scheme, where new keys are generated and distributed to each node as DPoS consensus nodes are elected; gated signatures limit the cases where a single or a few nodes can do evil.