LuxFHE Solidity

FHE-enabled Smart Contract Library for Lux Network

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⚠️ Important IP Notice

This library uses Lux's independent FHE implementation:

• ✅ Interfaces with github.com/luxfi/tfhe (our Go TFHE)
• ✅ Precompiles implemented in lux/evm/precompile/contracts/fhe/
• ✅ NO dependency on Zama or any third-party FHE code
• ✅ Protected by Lux Industries patent portfolio

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Overview

Solidity library for writing confidential smart contracts on Lux Network. Enables operations on encrypted data directly in smart contracts.

Installation

npm install @luxfhe/solidity
# or
forge install luxfhe/solidity

Quick Start

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.24;

import "@luxfhe/solidity/FHE.sol";

contract ConfidentialCounter {
    euint32 private counter;
    
    constructor() {
        counter = FHE.asEuint32(0);
    }
    
    function increment(inEuint32 calldata encryptedAmount) public {
        euint32 amount = FHE.asEuint32(encryptedAmount);
        counter = FHE.add(counter, amount);
    }
    
    function getEncrypted() public view returns (euint32) {
        return counter;
    }
}

Encrypted Types

Type	Description
ebool	Encrypted boolean
euint8	Encrypted 8-bit unsigned integer
euint16	Encrypted 16-bit unsigned integer
euint32	Encrypted 32-bit unsigned integer
euint64	Encrypted 64-bit unsigned integer
euint128	Encrypted 128-bit unsigned integer
euint160	Encrypted Ethereum address
euint256	Encrypted EVM word
eaddress	Encrypted address type

Operations

Arithmetic

• FHE.add(a, b) - Addition
• FHE.sub(a, b) - Subtraction
• FHE.mul(a, b) - Multiplication

Comparison

• FHE.eq(a, b) - Equal
• FHE.ne(a, b) - Not equal
• FHE.lt(a, b) - Less than
• FHE.le(a, b) - Less than or equal
• FHE.gt(a, b) - Greater than
• FHE.ge(a, b) - Greater than or equal

Bitwise

• FHE.and(a, b) - Bitwise AND
• FHE.or(a, b) - Bitwise OR
• FHE.xor(a, b) - Bitwise XOR
• FHE.not(a) - Bitwise NOT
• FHE.shl(a, n) - Left shift
• FHE.shr(a, n) - Right shift

Control Flow

• FHE.select(condition, a, b) - Encrypted ternary

Precompile Addresses

Address	Operation	Gas Cost
0x0080	FheAdd	50,000
0x0081	FheSub	50,000
0x0082	FheMul	150,000
0x0083	FheDiv	200,000
0x0090	FheEq	30,000
0x0091	FheLt	30,000
0x00A0	FheDecrypt	500,000

Contract Templates

ConfidentialERC20

import "@luxfhe/solidity/token/ConfidentialERC20.sol";

contract MyToken is ConfidentialERC20 {
    constructor() ConfidentialERC20("My Token", "MTK") {
        _mint(msg.sender, FHE.asEuint256(1000000 * 10**18));
    }
}

ConfidentialGovernance

import "@luxfhe/solidity/governance/ConfidentialGovernorAlpha.sol";

Architecture

Solidity Contracts (this library)
        ↓
FHE Precompiles (lux/evm/precompile/contracts/fhe/)
        ↓
Go TFHE Library (github.com/luxfi/tfhe)
        ↓
Lattice Primitives (github.com/luxfi/lattice)

License

Lux Research License with Patent Reservation

• ✅ Free for research and academic use
• ✅ Free on Lux Network (mainnet/testnet)
• 📧 Commercial license required for other networks

Contact: [email protected]

Related

• github.com/luxfi/tfhe - Go TFHE implementation
• github.com/luxfi/standard - Full contract library
• docs.lux.network/fhe - Documentation

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