# 隱私 & 區塊鏈 *2025.03.29* *Jeff / FoodChain* --- ## Agenda * About Me * Motivation * ZKP * Applications in ZKP --- ## About Me * Jeff aka FoodChain * zkmopro gpu acceleration * grantee @Hylé * privacy-preserved project * interested in zk & blockchain --- ## Motivation * Data leaking/ Selling (Facebook?) * Blockchain * Transparent * Immutable * Decentralized * private vs. public ---- ## They already exist? You might had used * a e2e encryption in your Whatsup. * A TLS protocol in https. * ... ---- > *Customers don’t know what they want until you show them* > Steve Jobs --- ### Zero Knowledge Proof （零知識證明） * You can "prove a statement without revealing the important information" * Prover: 提出證明的人 * Verifier: 驗證證明的人 * ZK-SNARKs (Succinct Non-Interactive Argument of Knowledge) * Groth16 ---- ## Theoritical Def * 完整性：若 Prover 知道 statement，則他可以說服 Verifier * 安全性：若 Prover 不知道 statement，則他只能以很小的機率「欺騙」 Verifier * 零知識證明：在這個系統中，Verifier 不會從 Prover 得到 statement 以外的任何資訊。 ---- ### Example1: Where's Waldo? 你知道 Waldo 在哪裏，但是在不直接指出 Waldo 的情況下說明。 ``` p = 1 - (1 / x)^n ```  ---- ### Example2: Alibaba ``` p = 1 - (1 / 2)^n n=15: p = 0.0000305176 = 0.003...% ```  ---- ## Interactive & Non-Interactive * 交互式 vs. 非交互式 * 多次提問 * 一次挑戰 * ZK-SNARK: non-interactive * Famous example: Groth16 ---- ## A ZKP system * Prover -> prove statement to -> Verifier * Prover has extro-ordinary computational power * Verifier has limited resources  * Normally, verifier can be a smart contract. --- ## Application in ZKP * Zcash * Tornado Cash * Semaphore * zkpassport * Rollup in blockchain: * with ZK: aztec, etc * without ZK: Starknet, etc ---- ## Privacy Developing - tornado cash  ---- ## Privacy Developing - zkpassport * Prove your are above 18. * Prove your nationality. * Prove you are from EU, ASEA, etc. * Prove you are a real person. > WITHOUT REVEALING ANYTHING!!!!!! --- # Thank you :smile: * my portfolio: [foodchain1028.com](https://foodchain1028.com) * my linkedin: [linkedin](https://linkedin.com/in/fu-chuan-chung) * my github: [foodchain1028](https://github.com/FoodChain1028)