Skip to content

0xRowan/erc-8086-reference

BranchesTags

Folders and files

NameName
Last commit message
Last commit date

Latest commit

 

History

11 Commits
contracts
contracts
 
 
deployments
deployments
 
 
docs
docs
 
 
examples
examples
 
 
.gitignore
.gitignore
 
 
LICENSE
LICENSE
 
 
README.md
README.md
 
 

Repository files navigation

ERC-8086: Privacy Token Standard

A minimal interface for native privacy-preserving fungible tokens on Ethereum

ERC Status ERC Status License: CC0-1.0

Overview

This repository contains two complementary ERC standards for privacy-preserving tokens on Ethereum:

Standard Name Description
ERC-8086 Privacy Token (IZRC20) Foundation layer - minimal interface for native privacy tokens
ERC-8085 Dual-Mode Token Application layer - combines ERC-20 and ERC-8086 in one token

Important: ERC-8085 and ERC-8086 are independent reference implementations. They share no code dependencies and can be deployed separately. This repository hosts both for convenience, but each standard has its own complete implementation in contracts/erc8085/ and contracts/erc8086/.

Ecosystem Stack:
┌─────────────────────────────────────┐
│  Applications (DeFi, DAO, Gaming)   │
├─────────────────────────────────────┤
│  ERC-8085: Dual-Mode Token          │  ← Public + Privacy in one token
│  Wrapper Protocols (ERC-20→ZRC-20)  │  ← Privacy for existing tokens
├─────────────────────────────────────┤
│  ERC-8086: IZRC20 Privacy Interface │  ← Foundation layer
├─────────────────────────────────────┤
│  Ethereum L1 / L2s                  │
└─────────────────────────────────────┘

ERC-8086: The Foundation

ERC-8086 defines IZRC20, a minimal interface standard for native privacy tokens. It enables:

  • Wrapper Protocols: Add privacy to existing ERC-20 tokens (DAI → zDAI → DAI)
  • Dual-Mode Tokens: Combine public (ERC-20) and private (ZRC-20) modes in one contract

ERC-8085: Dual-Mode Token

ERC-8085 builds on ERC-8086 to create tokens that support both transparent and privacy modes:

Single Token Contract
  ↓
Public Mode (ERC-20) ←→ Privacy Mode (ZK-SNARK)
  ↓                           ↓
DeFi/DEX Trading          Private Holdings

Key Features:

  • toPrivacy() - Convert public tokens to privacy mode
  • toPublic() - Convert privacy tokens back to public mode
  • Full ERC-20 compatibility for DeFi integration
  • Unified liquidity (no separate wrapped token)

Live Testnet Deployments

Both implementations are deployed and verified on Base Sepolia. Anyone can interact with and verify the contracts.

Try It Now

Standard Demo App
ERC-8086 (Native Privacy Token) testnative.zkprotocol.xyz
ERC-8085 (Dual-Mode Token) testdmt.zkprotocol.xyz

ERC-8086: Native Privacy Token Contracts

Contract Address Basescan
PrivacyTokenFactory 0x04df6DbAe3BAe8bC91ef3b285d0666d36dda24af View
PrivacyToken (Implementation) 0xa025070b46a38d5793F491097A6aae1A6109000c View
MintVerifier 0x1C9260008DA7a12dF2DE2E562dC72b877f4B9a4b View
MintRolloverVerifier 0x9423767D08eF34CEC1F1aD384e2884dd24c68f5B View
ActiveTransferVerifier 0x14834a1b1E67977e4ec9a33fc84e58851E21c4Aa View
FinalizedTransferVerifier 0x1b7c464ed02af392a44CE7881081d1fb1D15b970 View
RolloverTransferVerifier 0x4dd4D44f99Afb3AE4F4e8C03BAdA2Ff84E75f9Cb View

ERC-8085: Dual-Mode Token Contracts

Contract Address Basescan
DualModeTokenFactory 0xf5c16f708777cCb57C3A8887065b4EC02eAf9130 View
DualModeToken (Implementation) 0x1EFab166064AaD33fcB6074Ec8bA6302013C965C View
MintVerifier 0xC655b758f07bAaE8B956c95b055424a5c3B04e79 View
MintRolloverVerifier 0x9a6898B2e6C963EA81D17dCB9B0D483B590e168f View
ActiveTransferVerifier 0x7159EcAc6d1BB1433922b597fc2887dCA33a3A62 View
FinalizedTransferVerifier 0x0f9b6F788774671C8c47D8adE9D36E884c96580D View
RolloverTransferVerifier 0x0B22df9887351Ecfb403cfB27056f3A371F3bD92 View

Network: Base Sepolia (Chain ID: 84532)

Interface Specification

interface IZRC20 {
    // Events
    event CommitmentAppended(uint32 indexed subtreeIndex, bytes32 commitment, uint32 indexed leafIndex, uint256 timestamp);
    event NullifierSpent(bytes32 indexed nullifier);
    event Minted(address indexed minter, bytes32 commitment, bytes encryptedNote, uint32 subtreeIndex, uint32 leafIndex, uint256 timestamp);
    event Transaction(bytes32[2] newCommitments, bytes[] encryptedNotes, uint256[2] ephemeralPublicKey, uint256 viewTag);

    // Metadata (OPTIONAL but RECOMMENDED)
    function name() external view returns (string memory);
    function symbol() external view returns (string memory);
    function decimals() external view returns (uint8);
    function totalSupply() external view returns (uint256);

    // Core Functions
    function mint(uint8 proofType, bytes calldata proof, bytes calldata encryptedNote) external payable;
    function transfer(uint8 proofType, bytes calldata proof, bytes[] calldata encryptedNotes) external;
}

Key Concepts

Term Description
Commitment Cryptographic binding of value and ownership (hides amount & recipient)
Nullifier Unique identifier proving a commitment is spent (prevents double-spending)
Note Off-chain encrypted data (amount, publicKey, randomness) for recipient
View Tag Single-byte scanning optimization (~99.6% filtering efficiency)
Proof Type Routes to different verifiers (Active/Finalized/Rollover transfers)

Architecture: Dual-Layer Merkle Tree

This implementation uses a dual-layer architecture for scalability:

┌─────────────────────────────────────────────┐
│           Root Tree (20 levels)             │  ← Archives finalized subtrees
│         Capacity: 1,048,576 subtrees        │
├─────────────────────────────────────────────┤
│         Active Subtree (16 levels)          │  ← Recent commitments
│         Capacity: 65,536 notes              │  ← Fast proof generation
└─────────────────────────────────────────────┘

Total Capacity: 68.7 billion notes

Benefits:

  • 2-3x faster proof generation for active transfers
  • Decades of capacity without architectural changes
  • Efficient client synchronization (scan only active subtree)

Proof Types

Type Value Description Use Case
Active Transfer 0 Both inputs from active subtree Most common (~90% of txs)
Finalized Transfer 1 Inputs from finalized (historical) tree Spending old notes
Rollover Transfer 2 Triggers subtree finalization When active subtree is full

Repository Structure

erc-8086-reference/
├── README.md                           # This file
├── contracts/
│   ├── erc8086/                        # ERC-8086: Native Privacy Token (standalone)
│   │   ├── README.md                   # ERC-8086 implementation guide
│   │   ├── interfaces/
│   │   │   ├── IZRC20.sol              # Core privacy token interface
│   │   │   └── IVerifier.sol           # ZK verifier interfaces (12/13 signals)
│   │   └── reference/
│   │       ├── PrivacyToken.sol        # Privacy token implementation
│   │       └── PrivacyTokenFactory.sol # Factory for deploying privacy tokens
│   │
│   └── erc8085/                        # ERC-8085: Dual-Mode Token (standalone)
│       ├── README.md                   # ERC-8085 implementation guide
│       ├── interfaces/
│       │   ├── IZRC20.sol              # Privacy interface (independent copy)
│       │   ├── IVerifier.sol           # ZK verifier interfaces (13/14 signals)
│       │   └── IDualModeToken.sol      # Dual-mode token interface
│       └── reference/
│           ├── PrivacyToken.sol        # Base privacy layer (abstract)
│           ├── DualModeToken.sol       # Dual-mode token implementation
│           └── DualModeTokenFactory.sol # Factory for deploying dual-mode tokens
│
├── deployments/
│   ├── erc8086/
│   │   └── base-sepolia.json           # ERC-8086 deployment addresses
│   └── erc8085/
│       └── base-sepolia.json           # ERC-8085 deployment addresses
│
├── docs/
│   ├── erc-8086.md                     # ERC-8086 full specification
│   └── erc-8085.md                     # ERC-8085 full specification
│
└── examples/
    └── interaction.md                  # How to interact with contracts

Note: erc8085/ and erc8086/ are independent implementations with no shared code. Each has its own interfaces, verifiers, and contracts. The verifier interfaces differ (ERC-8085 has additional conversionAmount field).

Links

ERC-8086 (Native Privacy Token)

ERC-8085 (Dual-Mode Token)

Security Considerations

  1. Nullifier Uniqueness: Each nullifier can only be spent once
  2. Proof Verification: All zk-SNARK proofs verified on-chain before state changes
  3. Merkle Tree Integrity: Append-only structure prevents history modification
  4. Circuit Soundness: Enforces value conservation and ownership proofs

Community

License

This project is licensed under CC0 1.0 Universal.

About

No description, website, or topics provided.

Resources

Readme

License

CC0-1.0 license
Activity

Stars

10 stars

Watchers

1 watching

Forks

3 forks
Report repository

Releases

No releases published

Packages

 
 
 

Contributors

Languages