Sentinel Shield Protocol
SHIELD Token & Staking Contracts
| Contract | Address |
|---|---|
| SHIELD Token | 0xfD1b4b7Fc0Ede39273f8818a7E350341E264A959 |
| SHIELD Staking | 0xd31F82f94b72F21982d78e204487ac92BfE30d01 |
This document presents the findings of a comprehensive security audit conducted on the Sentinel Shield smart contracts deployed on the BlockStar Mainnet. The audit covered two primary contracts: the SHIELD Token (BSRC-20) and the SHIELD Staking Contract.
| Category | SHIELD Token | Staking Contract |
|---|---|---|
| Critical Issues | 0 Found | 0 Found |
| High Risk Issues | 0 Found | 0 Found |
| Medium Risk Issues | 0 Found | 1 Found (Resolved) |
| Low Risk Issues | 1 Found (Resolved) | 2 Found (Acknowledged) |
| Informational | 2 Notes | 3 Notes |
| Overall Status | PASSED | PASSED |
Both contracts have successfully passed the security audit with no critical or high-risk vulnerabilities identified. The contracts follow industry best practices for security, including proper access control, reentrancy protection, and safe mathematical operations. All identified medium and low-risk issues have been either resolved or acknowledged with acceptable mitigations in place.
The audit scope includes a thorough examination of the following smart contracts and their associated functionality:
Our audit methodology combines automated analysis tools with manual code review to ensure comprehensive coverage of potential security issues.
| Severity | Description |
|---|---|
| Critical | Exploitable vulnerabilities that can lead to loss of funds or contract takeover |
| High | Significant issues that could cause unexpected behavior or partial fund loss |
| Medium | Issues that could cause inconvenience or minor losses under specific conditions |
| Low | Best practice violations or minor issues with minimal security impact |
| Informational | Suggestions for code quality improvement or gas optimization |
| Property | Value |
|---|---|
| Contract Name | SHIELDToken |
| Token Standard | BSRC-20 (BSRC-20 Compatible) |
| Compiler Version | Solidity ^0.8.19 |
| Total Supply | 10,000,000 SHIELD (fixed) |
| Decimals | 18 |
| Mintable | No (fixed supply at deployment) |
| Burnable | Yes (owner only) |
| Pausable | Yes (trading enable/disable) |
The contract uses Solidity 0.8+ which includes built-in overflow/underflow protection. No external calls are made before state changes, following the checks-effects-interactions pattern.
Owner-only functions are properly protected with the onlyOwner modifier from OpenZeppelin's Ownable contract. Critical functions include: enableTrading(), setExcludedFromLimits(), setMaxTransferAmount(), and burn().
Solidity 0.8.19 provides automatic overflow/underflow checks. All arithmetic operations are protected by default compiler checks.
The contract correctly implements all required BSRC-20 functions: totalSupply(), balanceOf(), transfer(), approve(), transferFrom(), and allowance(). Events Transfer and Approval are emitted correctly.
| Feature | Implementation | Status |
|---|---|---|
| Transfer Cooldown | 30 seconds between transfers per address | SECURE |
| Max Transfer Amount | Configurable limit (default 1% of supply) | SECURE |
| Trading Enable | Owner can enable/disable trading | SECURE |
| Excluded Addresses | Whitelist for DEX/staking contracts | SECURE |
Description: The constructor did not validate that the treasury address parameter is not the zero address. This could result in tokens being sent to an unrecoverable address.
Recommendation: Add require(treasury != address(0), "Invalid treasury") check in constructor.
Resolution: The team has implemented the recommended check in the deployed contract.
| Property | Value |
|---|---|
| Contract Name | SHIELDStaking |
| Compiler Version | Solidity ^0.8.19 |
| Security Features | ReentrancyGuard, Ownable |
| Reward Rate | 5% APR |
| Minimum Stake | 100 SHIELD |
| Unstake Cooldown | 7 days |
| Validator Threshold | 10,000 SHIELD |
| Function | Access | Reentrancy Protected | Status |
|---|---|---|---|
stake(uint256) | Public | Yes (nonReentrant) | SECURE |
requestUnstake(uint256) | Public | Yes (nonReentrant) | SECURE |
unstake() | Public | Yes (nonReentrant) | SECURE |
emergencyUnstake() | Public | Yes (nonReentrant) | SECURE |
claimRewards() | Public | Yes (nonReentrant) | SECURE |
compoundRewards() | Public | Yes (nonReentrant) | SECURE |
fundRewardPool(uint256) | Owner Only | Yes (nonReentrant) | SECURE |
emergencyWithdraw(uint256) | Owner Only | Yes (nonReentrant) | SECURE |
All state-modifying functions use OpenZeppelin's ReentrancyGuard with the nonReentrant modifier. The contract follows the checks-effects-interactions pattern correctly.
Rewards are calculated using a time-weighted formula with proper precision handling. The 5% APR is calculated per-second to ensure accurate distributions regardless of claim timing. No precision loss vulnerabilities were identified.
The 7-day unstake cooldown is enforced through block.timestamp comparisons. This mechanism prevents flash loan attacks and ensures stakers have genuine commitment to the protocol.
Emergency unstake allows users to withdraw immediately while forfeiting rewards. Owner emergency withdrawal is protected by onlyOwner and emits events for transparency. Both functions are appropriately designed for emergency scenarios.
Description: If the reward pool is exhausted, claimRewards() would fail for users with pending rewards. This could temporarily lock user funds until the pool is replenished.
Recommendation: Implement a check that allows partial reward claims when pool is low, or add monitoring alerts for low pool balance.
Resolution: The team implemented reward availability checks and added monitoring for pool levels. Users can now claim available rewards even if less than total pending.
Description: There is no upper limit on individual stake amounts, which could lead to high reward concentration among large holders.
Team Response: This is intentional to allow institutional participation. The validator threshold system and governance mechanisms provide natural balance to large stakers.
Description: Reward calculations depend on block.timestamp which can be slightly manipulated by miners.
Team Response: Acknowledged as acceptable for staking use case where precision is not critical. The potential manipulation window is minimal and economically insignificant.
| ID | Contract | Severity | Title | Status |
|---|---|---|---|---|
| T-01 | Token | Low | Missing Zero Address Check | Resolved |
| S-01 | Staking | Medium | Reward Pool Exhaustion | Resolved |
| S-02 | Staking | Low | No Maximum Stake Limit | Acknowledged |
| S-03 | Staking | Low | Timestamp Dependence | Acknowledged |
Both contracts demonstrate reasonable gas efficiency. The following optimizations were noted and suggested for future versions:
| Function | Current Gas | Optimization Opportunity |
|---|---|---|
stake() | ~85,000 | Consider batch storage writes |
claimRewards() | ~65,000 | Optimized - no changes needed |
transfer() | ~52,000 | Standard BSRC-20, acceptable |
compoundRewards() | ~95,000 | Consider single storage update |
| Category | Assessment | Notes |
|---|---|---|
| Code Documentation | Good | NatSpec comments present on public functions |
| Error Messages | Good | Descriptive require statements throughout |
| Event Emissions | Good | Events emitted for all state changes |
| Access Control | Excellent | OpenZeppelin Ownable properly implemented |
| Upgrade Path | N/A | Non-upgradeable design (intentional) |
| Test Coverage | Good | Core functionality tested |
This security audit of the Sentinel Shield smart contracts (SHIELD Token and SHIELD Staking) has been completed successfully. Both contracts demonstrate strong security practices and proper implementation of their intended functionality.
Both the SHIELD Token and Staking contracts meet security standards and are ready for mainnet deployment.