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Implements comprehensive multi-agent security including: - Agent registry with identity and capability management - Secure message bus with signing and verification - Multiple consensus mechanisms (simple majority, supermajority, unanimous, weighted, BFT) - Byzantine fault detection with reputation tracking - Trust relationship management - Message replay prevention Features: - Agent-to-agent authentication - Message integrity verification - Byzantine fault tolerance with 2f+1 consensus - Reputation-based agent scoring - Inconsistency detection - Comprehensive test coverage
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Pull Request Overview
This PR introduces multi-agent coordination security features to ShieldGents, adding comprehensive security controls for multi-agent systems including secure messaging, consensus mechanisms, and Byzantine fault detection.
- Adds multi-agent security module with agent registry, secure message bus, consensus engine, and Byzantine detector
- Adds comprehensive test suite for multi-agent security functionality
- Updates code formatting across multiple files for consistency (imports, string quotes, line breaks)
Reviewed Changes
Copilot reviewed 43 out of 44 changed files in this pull request and generated 5 comments.
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| File | Description |
|---|---|
| src/shieldgents/integrations/multi_agent_security.py | New module providing multi-agent coordination security with agent registry, secure messaging, consensus mechanisms, and Byzantine fault detection |
| tests/test_multi_agent_security.py | Complete test suite for the new multi-agent security module with 338 lines of comprehensive tests |
| src/shieldgents/integrations/init.py | Updates imports to include the new multi-agent security module |
| tests/test_sandbox.py | Removes unused imports (pytest, TimeoutException) |
| tests/conftest.py | Reformats configuration markers and fixtures for consistency |
| Multiple other files | Code formatting updates (string quotes, import ordering, line breaks) |
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| BROADCAST = "broadcast" | ||
| VOTE = "vote" | ||
| PROPOSAL = "proposal" | ||
| ACKNOWLEDGMENT = "acknowledgment" |
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Corrected spelling of 'acknowledgment' to 'acknowledgement'.
| ACKNOWLEDGMENT = "acknowledgment" | |
| ACKNOWLEDGMENT = "acknowledgement" |
| # Check for replay attack | ||
| if message.nonce in self.seen_nonces: | ||
| return False |
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The replay attack prevention using seen nonces could grow unbounded in memory. Consider implementing a time-based cleanup mechanism to remove old nonces or use a time window approach to prevent memory exhaustion in long-running systems.
| # In production, use proper asymmetric cryptography | ||
| message_data = json.dumps(message.to_dict(), sort_keys=True) | ||
| return hashlib.sha256(message_data.encode()).hexdigest() |
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The comment correctly identifies this as a placeholder, but this SHA256-only approach provides no authentication or integrity guarantees since there's no secret key. In production, this should use HMAC with a secret key or proper digital signatures with public/private key pairs.
| """Check simple majority (>50%).""" | ||
| if len(votes) < total // 2 + 1: | ||
| return None | ||
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| yes_votes = sum(1 for v in votes.values() if v["vote"]) | ||
| no_votes = len(votes) - yes_votes | ||
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| if yes_votes > total / 2: | ||
| return True | ||
| elif no_votes > total / 2: | ||
| return False | ||
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The simple majority check has incorrect logic. It requires votes from more than half of eligible voters before determining consensus, but should allow consensus determination once enough votes are cast to determine the outcome. For example, with 5 voters, if 3 vote 'yes', consensus is reached regardless of whether the remaining 2 have voted.
| """Check simple majority (>50%).""" | |
| if len(votes) < total // 2 + 1: | |
| return None | |
| yes_votes = sum(1 for v in votes.values() if v["vote"]) | |
| no_votes = len(votes) - yes_votes | |
| if yes_votes > total / 2: | |
| return True | |
| elif no_votes > total / 2: | |
| return False | |
| """Check simple majority (>50%). Allows early consensus if outcome is mathematically certain.""" | |
| yes_votes = sum(1 for v in votes.values() if v["vote"]) | |
| no_votes = len(votes) - yes_votes | |
| remaining_votes = total - len(votes) | |
| majority = total // 2 + 1 | |
| # If yes_votes already reaches majority, approve | |
| if yes_votes >= majority: | |
| return True | |
| # If no_votes already reaches majority, reject | |
| if no_votes >= majority: | |
| return False | |
| # If even with all remaining votes, yes_votes cannot reach majority, reject | |
| if yes_votes + remaining_votes < majority: | |
| return False | |
| # If even with all remaining votes, no_votes cannot reach majority, approve | |
| if no_votes + remaining_votes < majority: | |
| return True | |
| # Otherwise, outcome not yet determined |
| self.suspicious_behaviors[agent_id] = [] | ||
| self.suspicious_behaviors[agent_id].append(behavior) | ||
| else: | ||
| self.agent_reputations[agent_id] = min(1.0, self.agent_reputations[agent_id] + 0.01) |
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The reputation adjustment values (0.9 multiplier for malicious behavior, 0.01 addition for good behavior) are magic numbers that should be configurable parameters. This would allow tuning the reputation system based on specific use cases and security requirements.
This PR introduces multi-agent coordination security features to ShieldGents, adding comprehensive security controls for multi-agent systems including secure messaging, consensus mechanisms, and Byzantine fault detection.
Reviewed Changes
Copilot reviewed 43 out of 44 changed files in this pull request and generated 5 comments.
Show a summary per file