Decentralized network of oracles.
Proof of Oracle - system of validation of the information, transferred to blockchain or via blockchain from external sources. This is network of oracles, integrated with decentralized information trading platform. Proof of oracle is based on reputation-based ranking system, which evaluates honesty and professionalism of each oracle, independently of whether oracle is represented by human, or by software.
Decentralized experts system, based on reputation, which confirms correctness of transfer of the information into blockchain. Replaces Oracles automatisation by escrow and reputation-based system.