Very recently, Baum et al. developed a publicly auditable secure MPC system that ensures correctness, even when all computing nodes are covertly malicious, or all but a single node are actively malicious [18]. Their state-of-the-art results are based on a variation of SPDZ (pronounced speedz) [19] and depend on a public append-only bulletin board, which stores the trail of each computation. This allows any auditing party to check the output is correct by comparing it to the public ledger’s trail of proofs. Our system uses the blockchain as the bulletin board, thus our overall security is reduced to that of the hosting blockchain.
I'm not a db or crypto expert, but this seems like a promising solution to the active adversary problem if you have an honest, healthy blockchain that is incentivized correctly.