Deep Dive

FinTech & Core Banking

Zero-Knowledge Financial Authorization Flow

sequenceDiagram autonumber actor Customer participant App as Banking App participant VajraPQC as PQC Gateway participant ZKEngine as ZK-SNARK participant Core as Core Banking Customer->>App: High-Value Transfer App->>VajraPQC: Encrypt Request App->>ZKEngine: Request Balance Proof Note over ZKEngine: Groth16 Proof (Bal >= 10k) ZKEngine-->>App: Returns Base64 ZK-Proof App->>Core: Submit Tx + Proof Core->>ZKEngine: Verify Groth16 Proof ZKEngine-->>Core: VALID Core-->>Customer: Approved (Zero-Trust)

1. PQC Request Encapsulation

When the customer initiates the high-value transfer, the request does not travel in plaintext or standard TLS. Instead, the Vajra PQC Gateway encapsulates the payload using ML-KEM-768 (formerly Kyber). The inner payload is then symmetrically encrypted with AES-256-GCM. This hybrid model protects the transaction against both classical and "Harvest Now, Decrypt Later" quantum attacks.

2. AI SOC Threat Triage

Before cryptographic proof generation begins, the Autonomous AI SOC evaluates the transaction's metadata (IP, Frequency, Time). Using a trained Ensemble Model (IsolationForest + One-Class SVM), it verifies the threat score is STABLE. If an anomaly is detected, the transaction would be routed to a Honey-Token vault instead.

3. Arkworks ZK-SNARK Proving (Groth16)

The core requirement is proving the user has at least $10,000 without revealing the actual balance (e.g., $450,200).

  • The ZK Engine compiles a Rank-1 Constraint System (R1CS) circuit in Rust.
  • It computes (Threshold + Difference) == Actual Secret inside the circuit.
  • A Groth16 proof is generated over the BN254 Elliptic Curve.
  • The proof is serialized to a Base64 string (~300 bytes) and returned.

4. Mathematical Verification

The Core Banking system receives the encrypted transaction intent alongside the ZK-Proof. It queries the ZK Engine to verify the Groth16 proof against the public parameters. The verification equation evaluates pairing checks. If valid, the core system approves the transaction with Zero-Trust certainty, completely unaware of the actual underlying balance.