Token Proof of Stake System

The token proof of stake system is a mechanism for stake allocation and validation based on token holdings, used to implement decentralized consensus and governance. This tutorial will explain how to implement a secure and reliable proof of stake system.

Features

Staking Mechanism
Validator Management
Reward Distribution
Slashing Mechanism
Delegation Mechanism

Contract Implementation

solidity

// SPDX-License-Identifier: MIT
pragma solidity ^0.8.0;

import "@openzeppelin/contracts/token/ERC20/IERC20.sol";
import "@openzeppelin/contracts/token/ERC20/utils/SafeERC20.sol";
import "@openzeppelin/contracts/access/Ownable.sol";
import "@openzeppelin/contracts/security/ReentrancyGuard.sol";
import "@openzeppelin/contracts/utils/math/SafeMath.sol";

/**
 * @title ProofOfStake
 * @dev Proof of stake contract implementation
 */
contract ProofOfStake is Ownable, ReentrancyGuard {
    using SafeMath for uint256;
    using SafeERC20 for IERC20;

    // Validator information
    struct Validator {
        uint256 stake;              // Staked amount
        uint256 rewards;            // Accumulated rewards
        uint256 lastRewardBlock;    // Last reward block
        uint256 delegatedStake;     // Total delegated stake
        bool isActive;              // Whether active
        bool isJailed;              // Whether jailed
    }

    // Delegation information
    struct Delegation {
        uint256 stake;              // Delegated amount
        uint256 rewards;            // Accumulated rewards
        uint256 lastRewardBlock;    // Last reward block
    }

    // Staking configuration
    struct StakingConfig {
        uint256 minValidatorStake;   // Minimum validator stake
        uint256 minDelegationStake;  // Minimum delegation stake
        uint256 maxValidators;       // Maximum validator count
        uint256 validatorCommission; // Validator commission rate
        uint256 unbondingTime;       // Unbonding time
        uint256 slashingRate;        // Slashing rate
    }

    // State variables
    IERC20 public stakingToken;                          // Staking token
    mapping(address => Validator) public validators;      // Validator mapping
    mapping(address => mapping(address => Delegation)) public delegations;  // Delegation mapping
    address[] public validatorSet;                       // Validator set
    StakingConfig public config;                         // Staking configuration
    uint256 public totalStaked;                          // Total staked amount
    uint256 public epochNumber;                          // Current epoch
    uint256 public epochBlocks;                          // Blocks per epoch
    uint256 public rewardPerBlock;                       // Reward per block

    // Unbonding request
    struct UnbondingRequest {
        uint256 amount;             // Unbonding amount
        uint256 completionTime;     // Completion time
    }
    mapping(address => UnbondingRequest[]) public unbondingRequests;

    // Events
    event ValidatorRegistered(address indexed validator, uint256 stake);
    event ValidatorUpdated(address indexed validator, uint256 stake);
    event ValidatorRemoved(address indexed validator);
    event Delegated(address indexed delegator, address indexed validator, uint256 amount);
    event Undelegated(address indexed delegator, address indexed validator, uint256 amount);
    event RewardsClaimed(address indexed account, uint256 amount);
    event ValidatorSlashed(address indexed validator, uint256 amount);
    event EpochCompleted(uint256 indexed epochNumber);

    /**
     * @dev Constructor
     */
    constructor(
        address _stakingToken,
        uint256 _epochBlocks,
        uint256 _rewardPerBlock,
        uint256 _minValidatorStake,
        uint256 _minDelegationStake,
        uint256 _maxValidators,
        uint256 _validatorCommission,
        uint256 _unbondingTime,
        uint256 _slashingRate
    ) {
        stakingToken = IERC20(_stakingToken);
        epochBlocks = _epochBlocks;
        rewardPerBlock = _rewardPerBlock;

        config = StakingConfig({
            minValidatorStake: _minValidatorStake,
            minDelegationStake: _minDelegationStake,
            maxValidators: _maxValidators,
            validatorCommission: _validatorCommission,
            unbondingTime: _unbondingTime,
            slashingRate: _slashingRate
        });
    }

    /**
     * @dev Register as validator
     */
    function registerValidator(uint256 _stake) external nonReentrant {
        require(_stake >= config.minValidatorStake, "Stake too low");
        require(!validators[msg.sender].isActive, "Already registered");
        require(validatorSet.length < config.maxValidators, "Max validators reached");

        stakingToken.safeTransferFrom(msg.sender, address(this), _stake);

        validators[msg.sender] = Validator({
            stake: _stake,
            rewards: 0,
            lastRewardBlock: block.number,
            delegatedStake: 0,
            isActive: true,
            isJailed: false
        });

        validatorSet.push(msg.sender);
        totalStaked = totalStaked.add(_stake);

        emit ValidatorRegistered(msg.sender, _stake);
    }

    /**
     * @dev Add validator stake
     */
    function addValidatorStake(uint256 _amount) external nonReentrant {
        require(validators[msg.sender].isActive, "Not a validator");
        require(!validators[msg.sender].isJailed, "Validator jailed");

        stakingToken.safeTransferFrom(msg.sender, address(this), _amount);

        validators[msg.sender].stake = validators[msg.sender].stake.add(_amount);
        totalStaked = totalStaked.add(_amount);

        emit ValidatorUpdated(msg.sender, validators[msg.sender].stake);
    }

    /**
     * @dev Delegate stake
     */
    function delegate(address _validator, uint256 _amount) external nonReentrant {
        require(validators[_validator].isActive, "Validator not active");
        require(!validators[_validator].isJailed, "Validator jailed");
        require(_amount >= config.minDelegationStake, "Stake too low");

        stakingToken.safeTransferFrom(msg.sender, address(this), _amount);

        Delegation storage delegation = delegations[msg.sender][_validator];
        if (delegation.stake == 0) {
            delegation.lastRewardBlock = block.number;
        }

        delegation.stake = delegation.stake.add(_amount);
        validators[_validator].delegatedStake = validators[_validator].delegatedStake.add(_amount);
        totalStaked = totalStaked.add(_amount);

        emit Delegated(msg.sender, _validator, _amount);
    }

    /**
     * @dev Request undelegation
     */
    function undelegate(address _validator, uint256 _amount) external nonReentrant {
        Delegation storage delegation = delegations[msg.sender][_validator];
        require(delegation.stake >= _amount, "Insufficient stake");

        // Update delegation information
        delegation.stake = delegation.stake.sub(_amount);
        validators[_validator].delegatedStake = validators[_validator].delegatedStake.sub(_amount);
        totalStaked = totalStaked.sub(_amount);

        // Create unbonding request
        unbondingRequests[msg.sender].push(UnbondingRequest({
            amount: _amount,
            completionTime: block.timestamp.add(config.unbondingTime)
        }));

        emit Undelegated(msg.sender, _validator, _amount);
    }

    /**
     * @dev Complete unbonding
     */
    function completeUnbonding() external nonReentrant {
        UnbondingRequest[] storage requests = unbondingRequests[msg.sender];
        uint256 totalAmount = 0;
        uint256 completedCount = 0;

        for (uint256 i = 0; i < requests.length; i++) {
            if (requests[i].completionTime <= block.timestamp) {
                totalAmount = totalAmount.add(requests[i].amount);
                completedCount++;
            } else {
                break;
            }
        }

        require(totalAmount > 0, "No completed unbonding");

        // Remove completed requests
        if (completedCount > 0) {
            for (uint256 i = completedCount; i < requests.length; i++) {
                requests[i - completedCount] = requests[i];
            }
            for (uint256 i = 0; i < completedCount; i++) {
                requests.pop();
            }
        }

        // Transfer unbonded tokens
        stakingToken.safeTransfer(msg.sender, totalAmount);
    }

    /**
     * @dev Calculate pending rewards
     */
    function calculateRewards(address _account, address _validator) public view returns (uint256) {
        Validator storage validator = validators[_validator];
        Delegation storage delegation = delegations[_account][_validator];

        if (delegation.stake == 0) {
            return 0;
        }

        uint256 blocksSinceLastReward = block.number.sub(delegation.lastRewardBlock);
        uint256 totalRewards = blocksSinceLastReward.mul(rewardPerBlock);
        
        uint256 validatorShare = totalRewards.mul(config.validatorCommission).div(100);
        uint256 delegatorShare = totalRewards.sub(validatorShare);
        
        return delegatorShare.mul(delegation.stake).div(validator.delegatedStake);
    }

    /**
     * @dev Claim rewards
     */
    function claimRewards(address _validator) external nonReentrant {
        require(validators[_validator].isActive, "Validator not active");
        
        uint256 rewards = calculateRewards(msg.sender, _validator);
        require(rewards > 0, "No rewards to claim");

        delegations[msg.sender][_validator].lastRewardBlock = block.number;
        delegations[msg.sender][_validator].rewards = delegations[msg.sender][_validator].rewards.add(rewards);

        stakingToken.safeTransfer(msg.sender, rewards);
        emit RewardsClaimed(msg.sender, rewards);
    }

    /**
     * @dev Batch claim rewards
     */
    function batchClaimRewards(address[] calldata _validators) external nonReentrant {
        uint256 totalRewards = 0;

        for (uint256 i = 0; i < _validators.length; i++) {
            address validator = _validators[i];
            if (validators[validator].isActive) {
                uint256 rewards = calculateRewards(msg.sender, validator);
                if (rewards > 0) {
                    delegations[msg.sender][validator].lastRewardBlock = block.number;
                    delegations[msg.sender][validator].rewards = delegations[msg.sender][validator].rewards.add(rewards);
                    totalRewards = totalRewards.add(rewards);
                }
            }
        }

        require(totalRewards > 0, "No rewards to claim");
        stakingToken.safeTransfer(msg.sender, totalRewards);
        emit RewardsClaimed(msg.sender, totalRewards);
    }

    /**
     * @dev Slash validator
     */
    function slashValidator(address _validator) external onlyOwner {
        require(validators[_validator].isActive, "Validator not active");
        require(!validators[_validator].isJailed, "Already jailed");

        uint256 slashAmount = validators[_validator].stake.mul(config.slashingRate).div(100);
        validators[_validator].stake = validators[_validator].stake.sub(slashAmount);
        validators[_validator].isJailed = true;
        totalStaked = totalStaked.sub(slashAmount);

        emit ValidatorSlashed(_validator, slashAmount);
    }

    /**
     * @dev Unjail validator
     */
    function unjailValidator(address _validator) external onlyOwner {
        require(validators[_validator].isActive, "Validator not active");
        require(validators[_validator].isJailed, "Not jailed");
        validators[_validator].isJailed = false;
    }

    /**
     * @dev Remove validator
     */
    function removeValidator(address _validator) external onlyOwner {
        require(validators[_validator].isActive, "Validator not active");

        uint256 totalAmount = validators[_validator].stake.add(validators[_validator].delegatedStake);
        validators[_validator].isActive = false;
        totalStaked = totalStaked.sub(totalAmount);

        // Remove validator from validator set
        for (uint256 i = 0; i < validatorSet.length; i++) {
            if (validatorSet[i] == _validator) {
                validatorSet[i] = validatorSet[validatorSet.length - 1];
                validatorSet.pop();
                break;
            }
        }

        emit ValidatorRemoved(_validator);
    }

    /**
     * @dev Update staking configuration
     */
    function updateConfig(
        uint256 _minValidatorStake,
        uint256 _minDelegationStake,
        uint256 _maxValidators,
        uint256 _validatorCommission,
        uint256 _unbondingTime,
        uint256 _slashingRate
    ) external onlyOwner {
        require(_validatorCommission <= 100, "Invalid commission");
        require(_slashingRate <= 100, "Invalid slashing rate");

        config.minValidatorStake = _minValidatorStake;
        config.minDelegationStake = _minDelegationStake;
        config.maxValidators = _maxValidators;
        config.validatorCommission = _validatorCommission;
        config.unbondingTime = _unbondingTime;
        config.slashingRate = _slashingRate;
    }

    /**
     * @dev Update reward per block
     */
    function updateRewardPerBlock(uint256 _rewardPerBlock) external onlyOwner {
        rewardPerBlock = _rewardPerBlock;
    }

    /**
     * @dev Update epoch blocks
     */
    function updateEpochBlocks(uint256 _epochBlocks) external onlyOwner {
        epochBlocks = _epochBlocks;
    }

    /**
     * @dev Complete epoch
     */
    function completeEpoch() external onlyOwner {
        epochNumber = epochNumber.add(1);
        emit EpochCompleted(epochNumber);
    }

    /**
     * @dev Get validator information
     */
    function getValidatorInfo(address _validator) external view returns (
        uint256 stake,
        uint256 rewards,
        uint256 lastRewardBlock,
        uint256 delegatedStake,
        bool isActive,
        bool isJailed
    ) {
        Validator storage validator = validators[_validator];
        return (
            validator.stake,
            validator.rewards,
            validator.lastRewardBlock,
            validator.delegatedStake,
            validator.isActive,
            validator.isJailed
        );
    }

    /**
     * @dev Get delegation information
     */
    function getDelegationInfo(address _delegator, address _validator) external view returns (
        uint256 stake,
        uint256 rewards,
        uint256 lastRewardBlock
    ) {
        Delegation storage delegation = delegations[_delegator][_validator];
        return (
            delegation.stake,
            delegation.rewards,
            delegation.lastRewardBlock
        );
    }

    /**
     * @dev Get unbonding requests
     */
    function getUnbondingRequests(address _account) external view returns (
        uint256[] memory amounts,
        uint256[] memory completionTimes
    ) {
        UnbondingRequest[] storage requests = unbondingRequests[_account];
        amounts = new uint256[](requests.length);
        completionTimes = new uint256[](requests.length);

        for (uint256 i = 0; i < requests.length; i++) {
            amounts[i] = requests[i].amount;
            completionTimes[i] = requests[i].completionTime;
        }

        return (amounts, completionTimes);
    }

    /**
     * @dev Emergency withdraw
     */
    function emergencyWithdraw(
        address _token,
        address _to,
        uint256 _amount
    ) external onlyOwner {
        require(_token != address(stakingToken), "Cannot withdraw staking token");
        require(_to != address(0), "Invalid recipient");
        IERC20(_token).safeTransfer(_to, _amount);
    }
}

Key Concepts

Staking Mechanism

The staking system supports:

Validator staking
Delegation staking
Unbonding mechanism
Reward distribution

Validator Management

Management functions include:

Registering validators
Updating stake
Slashing mechanism
Unjailing

Delegation Mechanism

Delegation functions include:

Delegating stake
Undelegating
Reward calculation
Reward claiming

Security Considerations

Staking Security
- Minimum stake limit
- Unbonding delay
- Slashing mechanism
- Permission verification
Reward Security
- Reward calculation
- Distribution rules
- Reward claiming limits
- Inflation control
System Security
- Reentrancy protection
- Permission management
- State checking
- Emergency control
Data Security
- State synchronization
- Data verification
- Error handling
- Event logging

Best Practices

Staking Management
- Reasonable minimum stake
- Appropriate unbonding period
- Fair distribution mechanism
- Effective slashing mechanism
Validator Management
- Strict准入条件
- Thorough monitoring
- Timely punishment measures
- Reasonable exit mechanism
Delegation Management
- Flexible delegation mechanism
- Transparent reward calculation
- Convenient operation process
- Complete information display
System Maintenance
- Regular checks
- Parameter optimization
- Security audits
- Upgrade plans

Extended Features

Dynamic validator set
Multi-layer delegation mechanism
Governance voting weight
Automatic reinvestment mechanism
Cross-chain staking

Application Scenarios

Network consensus
- Block validation
- Transaction confirmation
- Network security
- Consensus formation
Governance participation
- Proposal voting
- Parameter adjustment
- Protocol upgrade
- Community decision
Economic incentives
- Staking income
- Inflation distribution
- Ecological construction
- Long-term development

Summary

The proof of stake system is an important component of blockchain networks. Through this tutorial, you can:

Implement a complete staking mechanism
Ensure system security
Optimize user experience
Promote network development

Frequently Asked Questions (FAQ)

Basic Concepts

Q: What is proof of stake (PoS)?

A: Proof of stake is a consensus mechanism, characterized by:

Token staking
Validator election
Reward distribution
Slashing mechanism
Delegation mechanism

Q: What is the difference between a validator and a delegate?

A: The main differences include:

Validators run nodes, while delegates only need to stake
Validators need to meet the minimum stake requirements
Validators bear more responsibility and risks
Validators can earn commission income
Delegates have lower thresholds

Q: How to become a validator?

A: The steps to become a validator include:

Prepare enough staking tokens
Deploy validator nodes
Register validator identity
Wait for activation confirmation
Start validating work

Q: How to delegate stake?

A: The steps to delegate stake include:

Select a reliable validator
Prepare staking tokens
Authorize contract use
Execute delegation operation
Wait for confirmation to take effect

Q: What are the risks of PoS systems?

A: The main risks include:

Validator malicious behavior
Network attacks
Token price volatility
Staking token lock-up
Slashing losses

Q: How to ensure system security?

A: Security measures include:

Multi-factor verification
Slashing mechanism
Lock period setting
Equity distribution
Monitoring and warning

Q: How to optimize system performance?

A: Optimization methods include:

Batch processing
State caching
Gas optimization
Event optimization
Load balancing

Q: How to improve user experience?

A: Improvement measures include:

Clear interface
Real-time updates
Error handling
Status feedback
Operation guidance

Q: How to maintain the system?

A: Maintenance includes:

Regular monitoring
Parameter adjustment
Security audits
Version upgrades
Emergency response

Q: How to handle system upgrades?

A: Upgrade strategies include:

Compatibility testing
Gradual rollout
Data migration
Version control
Rollback plan

Q: How to integrate with other modules?

A: Integration methods include:

Standard interfaces
Event monitoring
State synchronization
Data validation
Error handling

Q: How to implement cross-chain staking?

A: Implementation approaches include:

Bridge protocols
Message passing
State verification
Asset mapping
Security measures

System Architecture

1. Core Components

Staking Module: Manages staking operations
Validator Module: Manages validators
Delegation Module: Manages delegations
Reward Module: Manages rewards
Security Module: Manages security

2. Process Flow

Validator registration
Token staking
Delegation processing
Reward calculation
Unbonding handling

3. State Management

Validator states
Delegation records
Reward distribution
System parameters
Security status

4. Security Mechanism

Access control
State verification
Transaction validation
Emergency handling
Event logging

Implementation Guidelines

1. Contract Setup

Initialize parameters
Set up validators
Configure rewards
Implement security

2. Operation Flow

Request validation
State updates
Reward calculation
Event emission
Error handling

3. Security Measures

Input validation
State checks
Access control
Emergency pause
Event logging

4. Optimization Strategies

Gas optimization
Batch processing
State caching
Code efficiency
Performance monitoring

Usage Examples

1. Register Validator

javascript

const stake = ethers.utils.parseEther("1000");
await stakingToken.approve(pos.address, stake);
await pos.registerValidator(stake);

2. Delegate Stake

javascript

const amount = ethers.utils.parseEther("100");
await stakingToken.approve(pos.address, amount);
await pos.delegate(validator, amount);

3. Claim Rewards

javascript

await pos.claimRewards(validator);

4. Undelegate

javascript

const amount = ethers.utils.parseEther("50");
await pos.undelegate(validator, amount);

Development Tips

Security First
- Thorough testing
- Security audits
- Error handling
- Access control
- Event logging
Performance Optimization
- Gas efficiency
- Batch processing
- State management
- Code optimization
- Cache usage
User Experience
- Clear interface
- Status feedback
- Error messages
- Operation guidance
- Documentation
Maintenance
- Regular monitoring
- Parameter tuning
- Version control
- Upgrade planning
- Emergency response

Future Extensions

Advanced Features
- Governance integration
- Cross-chain staking
- Advanced rewards
- Dynamic parameters
- Analytics tools
System Upgrades
- Protocol improvements
- Security enhancements
- Performance optimization
- Feature additions
- User experience improvements
Integration Options
- DeFi protocols
- Governance systems
- Cross-chain bridges
- Analytics platforms
- User interfaces

Token Proof of Stake System ​

Features ​

Contract Implementation ​

Key Concepts ​

Staking Mechanism ​

Validator Management ​

Delegation Mechanism ​

Security Considerations ​

Best Practices ​

Extended Features ​

Application Scenarios ​

Summary ​

Frequently Asked Questions (FAQ) ​

Basic Concepts ​

Operational Related ​

Security Related ​

Performance Related ​

Maintenance Related ​

Integration Related ​

System Architecture ​

1. Core Components ​

2. Process Flow ​

3. State Management ​

4. Security Mechanism ​

Implementation Guidelines ​

1. Contract Setup ​

2. Operation Flow ​

3. Security Measures ​

4. Optimization Strategies ​

Usage Examples ​

1. Register Validator ​

2. Delegate Stake ​

3. Claim Rewards ​

4. Undelegate ​

Development Tips ​

Future Extensions ​

Token Proof of Stake System

Features

Contract Implementation

Key Concepts

Staking Mechanism

Validator Management

Delegation Mechanism

Security Considerations

Best Practices

Extended Features

Application Scenarios

Summary

Frequently Asked Questions (FAQ)

Basic Concepts

Operational Related

Security Related

Performance Related

Maintenance Related

Integration Related

System Architecture

1. Core Components

2. Process Flow

3. State Management

4. Security Mechanism

Implementation Guidelines

1. Contract Setup

2. Operation Flow

3. Security Measures

4. Optimization Strategies

Usage Examples

1. Register Validator

2. Delegate Stake

3. Claim Rewards

4. Undelegate

Development Tips

Future Extensions