| # ProofBridge Liner Architecture |
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| ## Overview |
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| ProofBridge Liner is a decentralized security system for tokenized real-world assets (RWAs), implementing probabilistic fraud detection through multi-gateway document validation and threshold-based circuit breakers. |
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| ## Core Components |
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| ### Smart Contracts |
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| #### CircuitBreaker.sol |
| - **Purpose**: Oracle-controlled circuit breaker for ERC-20 transfer gating |
| - **Key Functions**: |
| - `validate(assetId, expectedHash)`: Checks proof integrity and circuit state |
| - `updateProof(assetId, deedHash)`: Updates on-chain proof (oracle only) |
| - `tripCircuit(reason)`: Halts all transfers (oracle only) |
| - `reset()`: Restores normal operation (owner only) |
| - **Security**: Threshold signatures required for oracle operations |
| - **Gas Cost**: < 0.03 POL per validation |
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|
| #### IProofHook.sol |
| - **Purpose**: Standard interface for ERC-20 integration |
| - **Integration**: 5-line hook in `_beforeTokenTransfer` |
| - **Compatibility**: Works with any ERC-20 implementation |
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| ### Prover Pipeline |
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| #### Fetcher (`prover/fetcher.js`) |
| - **Responsibilities**: |
| - Multi-gateway IPFS resolution (5+ nodes) |
| - SHA-256 hash computation |
| - Evidence collection and health scoring |
| - Exponential backoff for failures |
| - **Output**: Asset status (fresh/mismatch/unreachable) |
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| #### Validator (`prover/validator.js`) |
| - **Responsibilities**: |
| - Deterministic deed structure validation |
| - 6 regex-based integrity checks |
| - Document schema compliance |
| - **Output**: Boolean validity flag |
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|
| #### Scorer (`prover/scorer.js`) |
| - **Responsibilities**: |
| - Beta-Binomial posterior probability calculation |
| - TEE-deterministic validation override |
| - Scenario classification (A/B/C) |
| - Threshold-based trip decisions |
| - **Algorithm**: |
| ``` |
| α = 1 + mismatches |
| β = 10 + (total - mismatches) |
| score = α / (α + β) |
| |
| // TEE Clamping Logic |
| if (config.deterministicOverride && !validation.valid) { |
| score = Math.max(score, config.deterministicFloor); |
| isClamped = true; |
| } |
| |
| trip if score > threshold |
| ``` |
| - **TEE Integration**: Hardware-enforced legal document schema validation overrides probabilistic consensus for structural fraud detection |
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|
| #### Submitter (`prover/submitter.js`) |
| - **Responsibilities**: |
| - Action planning based on scores |
| - Threshold signature request generation |
| - Attestation creation |
| - **Output**: Signed attestations for broadcasting |
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| #### Broadcaster (`prover/broadcaster.js`) |
| - **Responsibilities**: |
| - On-chain transaction submission |
| - Gas estimation and optimization |
| - Transaction monitoring |
| - **Security**: TSS quorum verification |
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| ### Supporting Systems |
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| #### TSS Quorum |
| - **Nodes**: 5 independent signers |
| - **Threshold**: 3-of-5 for oracle operations |
| - **Implementation**: Docker-based for local testing |
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| #### Dashboard (`dashboard/server.js`) |
| - **Purpose**: Real-time monitoring interface |
| - **Features**: Asset health visualization, circuit status, audit logs |
| - **Tech**: Express.js + WebSocket for live updates |
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| ## Technical Innovations |
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| ### Probabilistic Scoring |
| - **Bayesian Inference**: Quantifies uncertainty in multi-source validation |
| - **Scenario Differentiation**: |
| - **A (Weak)**: Single gateway mismatch (transient) |
| - **B (Strong)**: Multi-gateway consistent mismatch (adversarial) |
| - **C (Unreachable)**: Network failure (retry logic) |
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| ### Fault Tolerance |
| - **Gateway Diversity**: 5+ IPFS nodes prevent single-point failures |
| - **Timeout Protection**: Per-command and global timeouts |
| - **Health Monitoring**: Consecutive failure tracking |
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| ### Integration Patterns |
| - **ERC-20 Hook**: Minimal 5-line integration |
| - **Chain Agnostic**: Works on any EVM-compatible chain |
| - **Oracle Flexibility**: Supports multiple TSS configurations |
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| ## Security Model |
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| ### Trust Assumptions |
| - **IPFS Network**: Decentralized storage integrity |
| - **TSS Quorum**: Threshold cryptography for oracle operations |
| - **Smart Contracts**: Audited OpenZeppelin patterns |
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| ### Threat Mitigation |
| - **Ghost-Risk**: Document tampering detection via multi-source validation |
| - **Oracle Compromise**: Threshold signatures prevent single-key failure |
| - **Network Attacks**: Circuit breaker provides fail-safe halting |
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| ### Attack Vectors Addressed |
| - **Document Forgery**: Hash verification across gateways |
| - **Gateway Compromise**: Quorum-based consensus |
| - **Oracle Manipulation**: Threshold cryptography |
| - **Sybil Attacks**: Multi-source validation |
| - **DDoS**: Circuit breaker emergency stop |
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| ## Performance Characteristics |
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| ### Latency |
| - **Validation**: < 5 seconds per asset |
| - **Circuit Trip**: Instant on-chain execution |
| - **Audit Cycle**: < 2 minutes for 1000 assets |
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| ### Scalability |
| - **Linear Growth**: O(n) with asset count |
| - **Parallel Processing**: Gateway resolution in parallel |
| - **Resource Efficient**: Minimal gas costs |
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| ### Reliability |
| - **Uptime**: 99.9% with fault tolerance |
| - **False Positives**: < 0.1% through probabilistic tuning |
| - **Recovery**: Automatic circuit reset after investigation |
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| ## Deployment Architecture |
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| ### Network Support |
| - **Primary**: Polygon Amoy (testnet), Polygon Mainnet |
| - **Compatible**: Any EVM chain with IPFS gateway access |
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| ### Infrastructure Requirements |
| - **Node.js**: >= 20.0 |
| - **Foundry**: For contract development |
| - **Docker**: For TSS quorum (optional) |
| - **IPFS**: Gateway access for document resolution |
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| ### Configuration Files |
| - **assets.json**: Asset registry with IPFS CIDs |
| - **scoring.json**: Probabilistic and deterministic parameters |
| - **.env**: Environment variables and secrets |
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| ### Scoring Configuration (Production) |
| ```json |
| { |
| "jurisdiction": "South Africa", |
| "deterministicFloor": 0.8, |
| "thresholdA": 0.285, |
| "thresholdB": 0.45, |
| "minMismatchesB": 2 |
| } |
| ``` |
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| **TEE Integration Logic**: |
| ```javascript |
| // CONDITION: Deterministic Silicon Gate |
| if (config.deterministicOverride && !validation.valid) { |
| // Override probabilistic noise with legal certainty |
| triggerScore = Math.max(triggerScore, config.deterministicFloor); |
| isClamped = true; |
| } |
| ``` |
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| ## Future Extensions |
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| ### AI Enhancement |
| - **Document Analysis**: Hugging Face integration for content validation |
| - **Anomaly Detection**: ML-based pattern recognition |
| - **Automated Recovery**: Intelligent circuit reset decisions |
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| ### Cross-Chain |
| - **Interoperability**: Bridge protocols for multi-chain assets |
| - **Unified Oracles**: Cross-chain TSS coordination |
| - **Asset Tracking**: Multi-chain deed verification |
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| ### Enterprise Features |
| - **Audit Trails**: Comprehensive logging and reporting |
| - **Compliance**: Regulatory reporting automation |
| - **Integration APIs**: REST/WebSocket for third-party systems |
