Zero-knowledge proof\nPublic.icon\n"Proving the fact of 'knowing a proposition' without revealing its content" is called a "Zero-Knowledge Proof" ZKP.\n\n\s>In cryptography, zero-knowledge proof is a method of proof in a conversation whereby one person proves to another that a statement is true, without revealing any knowledge beyond the validity of the statement. Zero-knowledge proof - Wikipedia\n\n\s>In fact, in realized methods, proofers and interrogators engage in a number of roundtrips, so they are also called Zero-Knowledge Interactive Proof ZKIP:Zero-Knowledge Interactive Proof. Old technology: Zero-knowledge interactive proof - Qiita\n\n\s>Unless the following prerequisites are met, it is impossible to perform zero-knowledge proofs at all.\n\s\s>The problem is known to the questioner\n\s\s>If you know the answer, the proof is also easy\n\s\sIt is practically impossible to solve the problem by brute force, because computational complexity explodes\n\n\s>In such problems, if\n\s\s> Transformation to another type of problem is easy, and if you know the correct answer, you know the correct answer to the problem after the transformation\n\s\s\sCommon divisorThis may be close to the concept of. Previous companies, interviews and appearances related to oneself.icon\n\s\s> Even when comparing the transformed problem with the original problem, the transformation rules are not easy to understand\n\s\s> Even if you know the correct answer to the transformed problem, you cannot know the correct answer to the original problem unless you know the transformation rules\n\s> If these conditions are met, ZKIP is possible.\n\nMotivation for interactive proof systems - Crypto study group\n\s["Zero-knowledge proof originally came from the model of interactive proof systems"]\n\sNP proof system\n\s\sToo difficult\n\sInteractive proof system (IPS)\n\s\s>The NP proof system is limited to the deterministic algorithm thath is to "validate if the problem is correct by the evidence given from the prover". It is thought that higher expressive power can be obtained by expanding it to a probabilistic algorithm (where "thought" is used because it is not clear whether NP is a full recursive subset of IP).\n\s\s> IP (interactive proof) is the natural probabilistic algorithm extension of NP. https://gyazo.com/cead0906e2fdec46594bf86880c6878b
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Authentication and digital signatures are some examples of where it is used. Although not mentioned in this article, it is also used for "scaling" (not privacy) to address the problem of processing Ethereum transactions. https://gyazo.com/dfa63ec68915eec09a7ad1c0c7e901ab
https://gyazo.com/5a3f8fb824a0063a6d2d542812d66fbe
The amount of reference materials is amazing.