What Are the Differences between Centralized, Decentralized, and Optimistic Oracle Models in Terms of Security and Cost?

Centralized oracles are single entities providing data. They are efficient and low-cost but represent a single point of failure and require complete trust in the provider.

Decentralized oracles aggregate data from multiple independent nodes, enhancing security and reliability by eliminating single points of failure, but this comes at a higher coordination cost. Optimistic oracles assume data is correct unless challenged.

Data is posted with a bond and can be disputed within a time window. This model is cheaper and faster than decentralized aggregation but relies on economic incentives and at least one honest challenger to ensure accuracy.