# ARC-20: 同质化代币标准

**Published by:** [Yaakov](https://paragraph.com/@yaakov/)
**Published on:** 2024-06-24
**URL:** https://paragraph.com/@yaakov/arc-20

## Content

Aleo 正在讨论中的ARC-20标准旨在为Aleo区块链提供代币互操作性和用户授权功能，类似于ERC-20。它允许代币轻松转账，并允许用户授权程序管理这些代币，特别适用于自动化金融应用。ARC-20标准的独特之处在于整合了Aleo的隐私特性，例如私有记录，提供用户在数字交易中的隐私和匿名性。这里我们将分别介绍这些方法。规范程序结构program token.aleo; mapping account: key as address.public; value as u64.public; record token: owner as address.private; amount as u64.private; struct approval: approver as address; spender as address; struct metadata: name as u128; // 16 bytes -> 16 characters with ASCII encoding symbol as u64; // 8 bytes -> 8 characters with ASCII encoding decimals as u8; total_supply as u64; mapping approvals: key as field.public; value as u64.public; 核心功能介绍1. 获取元数据function get_metadata: cast [name] [symbol] [decimals] [total_supply] into r0 as metadata; output r0 as metadata.public; 此函数返回代币的元数据，包括名称、符号、小数位和总供应量。这些信息有助于钱包和dApp正确显示代币信息。 2. 授权公共代币使用function approve_public: input r0 as address.public; // 授权的地址 input r1 as u64.public; // 授权的代币数量 cast self.caller r0 into r2 as approval; hash.bhp256 r2 into r3 as field; async approve_public r3 r1 into r4; output r4 as token.aleo/approve_public.future; finalize approve_public: input r0 as field.public; input r1 as u64.public; // 增加授权的代币数量 get.or_use approvals[r0] 0u64 into r2; add r1 r2 into r3; set r3 into approvals[r0]; 此函数允许代币持有者授权某个地址使用一定数量的代币。这个功能对于允许智能合约代表用户执行代币操作至关重要。 3. 取消授权function unapprove_public: input r0 as address.public; // 被取消授权的地址 input r1 as u64.public; // 取消的代币数量 cast self.caller r0 into r2 as approval; hash.bhp256 r2 into r3 as field; async unapprove_public r3 r1 into r4; output r4 as token.aleo/unapprove_public.future; finalize unapprove_public: input r0 as field.public; input r1 as u64.public; // 减少授权的代币数量 get approvals[r0] into r2; sub r2 r1 into r3; set r3 into approvals[r0]; 此函数撤销之前授权的代币数量，用于减少或完全撤销对某个地址的授权。 4. 从公共账户转账function transfer_from_public: input r0 as address.public; // 授权者 input r1 as address.public; // 接收者 input r2 as u64.public; // 转账数量 cast r0 self.caller into r3 as approval; hash.bhp256 r3 into r4 as field; async transfer_from_public r4 r0 r1 r2 into r5; output r5 as token.aleo/transfer_from_public.future; finalize transfer_from_public: input r0 as field.public; input r1 as address.public; input r2 as address.public; input r3 as u64.public; get approvals[r0] into r4; sub r4 r3 into r5; set r5 into approvals[r0]; get account[r1] into r6; sub r6 r3 into r7; set r7 into account[r1]; get.or_use account[r2] 0u64 into r8; add r8 r3 into r9; set r9 into account[r2]; 此函数实现从授权者账户向接收者账户的代币转账，用于实现代币的自动化管理和支付。 5. 公共代币转账function transfer_public: input r0 as address.public; // 接收者地址 input r1 as u64.public; // 转账数量 async transfer_public self.caller r0 r1 into r2; output r2 as token.aleo/transfer_public.future; finalize transfer_public: input r0 as address.public; input r1 as address.public; input r2 as u64.public; get.or_use account[r0] 0u64 into r3; sub r3 r2 into r4; set r4 into account[r0]; get.or_use account[r1] 0u64 into r5; add r5 r2 into r6; set r6 into account[r1]; 此函数将代币从调用者账户转移到指定的公共账户，实现简单的代币转账。 6. 私有代币转账function transfer_private: input r0 as token.record; // 代币记录 input r1 as address.private; // 接收者地址 input r2 as u64.private; // 转账数量 sub r0.amount r2 into r3; cast r0.owner r3 into r4 as token.record; cast r1 r2 into r5 as token.record; output r4 as token.record; output r5 as token.record; 此函数实现私有代币的转账，用于在保持交易隐私的情况下进行代币转移。 7. 私有代币转公共代币function transfer_private_to_public: input r0 as token.record; // 私有代币记录 input r1 as address.public; // 公共接收者地址 input r2 as u64.public; // 转账数量 sub r0.amount r2 into r3; cast r0.owner r3 into r4 as token.record; async transfer_private_to_public r1 r2 into r5; output r4 as token.record; output r5 as token.aleo/transfer_private_to_public.future; finalize transfer_private_to_public: input r0 as address.public; input r1 as u64.public; get.or_use account[r0] 0u64 into r2; add r2 r1 into r3; set r3 into account[r0]; 此函数将私有代币转换为公共代币，允许在公共账户中持有之前私有的代币。 8. 公共代币转私有代币function transfer_public_to_private: input r0 as address.public; // 公共账户地址 input r1 as u64.public; // 转账数量 cast r0 r1 into r2 as token.record; async transfer_public_to_private self.caller r1 into r3; output r2 as token.record; output r3 as token.aleo/transfer_public_to_private.future; finalize transfer_public_to_private: input r0 as address.public; input r1 as u64.public; get.or_use account[r0] 0u64 into r2; sub r2 r1 into r3; set r3 into account[r0]; 此函数将公共代币转换为私有代币，以确保交易隐私和安全。 通过这些规范和示例代码，ARC-20标准在Aleo区块链上实现了兼容且安全的同质化代币管理。 Aleo 官方链接：Aleo TwitterAleo DiscordAleo WebsiteAleo Github

## Publication Information

- [Yaakov](https://paragraph.com/@yaakov/): Publication homepage
- [All Posts](https://paragraph.com/@yaakov/): More posts from this publication
- [RSS Feed](https://api.paragraph.com/blogs/rss/@yaakov): Subscribe to updates
- [Twitter](https://twitter.com/yaakov90691264): Follow on Twitter