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<ol class="chapter"><li class="chapter-item expanded "><a href="0_0_zero_network.html"><strong aria-hidden="true">1.</strong> Zero Network</a></li><li class="chapter-item expanded "><a href="1_0_overview.html"><strong aria-hidden="true">2.</strong> Overview</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="1_1_what_is_privacy.html" class="active"><strong aria-hidden="true">2.1.</strong> What is Privacy</a></li><li class="chapter-item expanded "><a href="1_2_hide_transfer_amount.html"><strong aria-hidden="true">2.2.</strong> Hide Transfer Amount</a></li><li class="chapter-item expanded "><a href="1_3_gas_limit.html"><strong aria-hidden="true">2.3.</strong> Gas Limit</a></li><li class="chapter-item expanded "><a href="1_4_zero_knowledge_scheme.html"><strong aria-hidden="true">2.4.</strong> Zero Knowledge Scheme</a></li><li class="chapter-item expanded "><a href="1_5_transaction_constraints.html"><strong aria-hidden="true">2.5.</strong> Transaction Constraints</a></li></ol></li><li class="chapter-item expanded "><a href="2_0_transaction_constraints.html"><strong aria-hidden="true">3.</strong> Transaction Constraints</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="2_1_confidential_transfer.html"><strong aria-hidden="true">3.1.</strong> Confidential Transfer</a></li><li class="chapter-item expanded "><a href="2_2_confidential_smart_contract.html"><strong aria-hidden="true">3.2.</strong> Confidential Smart Contract</a></li></ol></li><li class="chapter-item expanded "><a href="3_0_primitive.html"><strong aria-hidden="true">4.</strong> Primitive</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="3_1_crypto.html"><strong aria-hidden="true">4.1.</strong> Crypto</a></li><li class="chapter-item expanded "><a href="3_2_jubjub.html"><strong aria-hidden="true">4.2.</strong> Jubjub</a></li><li class="chapter-item expanded "><a href="3_3_bls12_381.html"><strong aria-hidden="true">4.3.</strong> Bls12 381</a></li><li class="chapter-item expanded "><a href="3_4_elgamal.html"><strong aria-hidden="true">4.4.</strong> ElGamal</a></li><li class="chapter-item expanded "><a href="3_5_pairing.html"><strong aria-hidden="true">4.5.</strong> Pairing</a></li></ol></li><li class="chapter-item expanded "><a href="4_0_pallet.html"><strong aria-hidden="true">5.</strong> Pallet</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="4_1_plonk.html"><strong aria-hidden="true">5.1.</strong> Plonk</a></li><li class="chapter-item expanded "><a href="4_2_encrypted_balance.html"><strong aria-hidden="true">5.2.</strong> Encrypted Balance</a></li><li class="chapter-item expanded "><a href="4_3_confidential_transfer.html"><strong aria-hidden="true">5.3.</strong> Confidential Transfer</a></li></ol></li><li class="chapter-item expanded "><a href="5_0_related_tools.html"><strong aria-hidden="true">6.</strong> Related Tools</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="5_1_stealth_address.html"><strong aria-hidden="true">6.1.</strong> Stealth Address</a></li><li class="chapter-item expanded "><a href="5_2_pedersen_commitment.html"><strong aria-hidden="true">6.2.</strong> Pedersen Commitment</a></li><li class="chapter-item expanded "><a href="5_3_non_interactive_zero_knowlege_proof.html"><strong aria-hidden="true">6.3.</strong> Non Interactive Zero Knowledge Proof</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="5_3_1_qap.html"><strong aria-hidden="true">6.3.1.</strong> QAP</a></li><li class="chapter-item expanded "><a href="5_3_2_polynomial_commitment.html"><strong aria-hidden="true">6.3.2.</strong> Polynomial Commitment</a></li><li class="chapter-item expanded "><a href="5_3_3_homomorphic_encryption.html"><strong aria-hidden="true">6.3.3.</strong> Homomorphic Encryption</a></li></ol></li></ol></li><li class="chapter-item expanded "><a href="6_0_tutorial.html"><strong aria-hidden="true">7.</strong> Tutorial</a></li><li><ol class="section"><li class="chapter-item expanded "><a href="6_1_plonk_pallet.html"><strong aria-hidden="true">7.1.</strong> pallet-plonk</a></li><li class="chapter-item expanded "><a href="6_2_confidential_transfer.html"><strong aria-hidden="true">7.2.</strong> confidential_transfer</a></li></ol></li><li class="chapter-item expanded "><a href="7_0_frequent_errors.html"><strong aria-hidden="true">8.</strong> Frequent Errors</a></li></ol>
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<h1 class="menu-title">Zero Network Documentation</h1>
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<h1 id="what-is-privacy"><a class="header" href="#what-is-privacy">What is Privacy</a></h1>
<p>Before we describe our protocol, we would like to define what the <code>privacy</code> exactly means.</p>
<h2 id="confidential-vs-anonymous"><a class="header" href="#confidential-vs-anonymous">Confidential vs Anonymous</a></h2>
<p>There are two types of privacy level <code>confidential</code> and <code>anonymous</code>. The difference between them is that how much information we hide. The <code>confidential</code> means it hides the input and output. The <code>anonymous</code> means it hide the users related the transaction.</p>
<h2 id="transfer-example"><a class="header" href="#transfer-example">Transfer Example</a></h2>
<p>If the protocol supports <code>confidential</code>, the users would be able to hide the input and output. When users send the transaction, the input and output are going to be <code>balance</code>, <code>transfer amount</code> and <code>after balance</code>. The function needs to know that the transfer satisfies the conditions for example, the amount is not negative, the balance is more than transfer amount and so on. The <code>confidential</code> transactions can verify these conditions without revealing input and ouput values. We use the homomorphic encryption to realize this feature. You can see it on <a href="1_2_hide_transfer_amount.html"><code>Hide Transfer Amount</code></a> section.</p>
<p>If the protocol supports <code>anonymous</code>, the users would be able to hide the users information related to transactions in addition to <code>confidential</code>. When users transfer the assets, the users information related to transactions are going to be <code>sender</code> and <code>recipient</code>. There are some ways to hide users information and we describe some of them in related tools. The typical tool to hide the <code>sender</code> is the <a href="https://en.wikipedia.org/wiki/Ring_signature#:~:text=In%20cryptography%2C%20a%20ring%20signature,a%20particular%20set%20of%20people."><code>Ring Signature</code></a> and the <code>recipient</code> is the <a href="3_1_stealth_address.html">Stealth Address</a>.</p>
<h2 id="summarize"><a class="header" href="#summarize">Summarize</a></h2>
<p>To summarize the story, the <code>confidential</code> hides the transaction contents and the <code>anonymous</code> hides the transaction senders and recipients. We describe the contents and privacy level in table.</p>
<div class="table-wrapper"><table><thead><tr><th>Item</th><th>Confidential</th><th>Anonymous</th></tr></thead><tbody>
<tr><td>Balance</td><td>✅</td><td>✅</td></tr>
<tr><td>Transfer Amount</td><td>✅</td><td>✅</td></tr>
<tr><td>Sender</td><td>-</td><td>✅</td></tr>
<tr><td>Recipient</td><td>-</td><td>✅</td></tr>
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