Explore a comprehensive talk from Asiacrypt 2016 on the Iterated Random Oracle approach for finding loss in security reduction. Delve into two types of security reductions, focusing on IND security based on computational hard problems. Examine the core of encryption reduction in random oracles and learn about traditional approaches like the Trapdoor Test in Cash-Kiltz-Shoup. Discover the concept of Iterated Random Oracle, its query process, and challenge queries. Compare three theories and understand queries through tree representation. Gain insights into the proof of the presented theory and its applications in cryptography.