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Extractor in knowledge-soundness vs extractor in witness-extended emulation

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In the knowledge soundness definition page 8 of Groth16, it says: The extractor gets full access to the adversary’s state, including any random coins. My question is why full access? Why we just don't say oracle access to the adversary?

Then in the definition of witness-extended emulation (WEE) in Bulletproof (page 10) they say the extractor has oracle access to the transcript of interactions between the adversary (malicious prover) and the verifier.

I do not understand

  1. Why in the knowledge-soundness the extractor has full access to the adversary (why not just oracle access)?
  2. Why in WEE it does not have full access?[enter link description here][1]
ming alex avatar
in flag
Conceptually, I guess the knowledge extractor is equavlence to a oracle machine. The extractor is used to prove a speical soundness, i.e., proof of knowledge soundness. Therefore, we need to construct a powerful extractor interactiving with the prover to get the witness. A well-known method is called "rewinding" which can wind back the prover's action to extract secrets. So, if we want to prove the special soundness, we must prove the exstence of the extractor using some special strategies.
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