Mediated consensus is the consensus system used in the PolySwarm decentralized cyber threat market in which determining ground truth requires authorities with special expertise to produce it.
Polyswarm is different from prediction markets such as Augur because the ground truth is not 'universally observable'. In other words, the ground truth may not be apparent to somebody who hasn't conducted research or developed expert knowledge in a given field.
In short, mediated consensus is meant to incentivize people who have the proper expertise to participate as authorities in the system and to act in a way that's good for the overall health of the market.
Mediated consensus assigns consensus responsibilities to a specific set of market participants including observing ground truth regarding malintent of suspect files and artifacts to qualified experts, and consistently placing funds into the market for liquidity. Arbiters are selected from the most active Ambassadors; they determine ground truth of suspicious files, and are most rewarded by promoting the honesty of the system.
