Recently, I have been researching a question: if the majority of nodes in the oracle network are collectively bribed with huge benefits and submit incorrect price data, what can we do about it? This "majority bribery attack" sounds extreme, but for the entire DeFi ecosystem, it’s like a sword hanging overhead.

Until I thoroughly understood APRO's dual-layer oracle network, I realized how ingenious their solution is. It’s not just a technical patch, but a complete system of checks and balances. The logic is similar to a judicial system: the first layer consists of opposing prosecution and defense, and the second layer is the judge with the final say.

**Layer One: Mutual Oversight Among Data Collectors**

The first layer of APRO is built on a main network composed of OCMP nodes. These nodes are the core participants of the ecosystem, responsible for data collection, computation, and submission every day. Think of them as athletes in a sports arena, but this game has no traditional referees.

Nodes implement a "mutual supervision" system. Each node monitors the data from other nodes. If large-scale, suspicious anomalies are detected (such as prices collectively deviating from the market reality), an "appeal" can be made immediately. The benefit of this approach is obvious: attempting to commit long-term, large-scale fraud in front of everyone’s eyes is almost impossible.

**Layer Two: Reputation Mechanism and Final Arbitration**

When irreconcilable disputes arise in the first layer, the second layer is activated. This layer, based on historical performance and reputation scores, holds the final arbitration authority.