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William Rodriguez
William Rodriguez

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Non-repudiation in distributed ledgers: ECDSA P-256 digital signatures

#python

Shared secrets are an anti-pattern in distributed ledger systems. wFabricSecurity enforces public-key cryptography with ECDSA P-256 for uncompromising non-repudiation.

Day 02 of the wFabricSecurity Open-Source Engineering Series.

The Pain Points We Faced

  • Transmitting unsigned JSON payloads over internal networks susceptible to man-in-the-middle tampering
  • Inability to prove which off-chain worker originated a malicious ledger mutation
  • Incompatible signature formats between Python microservices and Go/Java Fabric peers

The Implementation 

from wFabricSecurity import FabricSecurity

security = FabricSecurity(me="SignerNode", msp_path="/opt/fabric/msp")
security.register_identity()

# Sign payload with node private key
payload = '{"action": "endorse_asset", "asset_id": "ASSET_9981"}'
signed_msg = security.create_message(recipient="CN=ConsensusPeer", content=payload)

# Recipient peer verifies ECDSA signature
is_valid = security.verify_message(signed_msg)
print(f"Signature mathematically verified: {is_valid}")
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Why This Architecture Wins

  • NIST P-256 Standard: Uses standard secp256r1 curve fully compatible with Fabric CA.
  • Non-Repudiation: Cryptographic proof that the sender generated the exact payload.
  • High-Speed C-Bindings: Fast ECDSA operations powered by the Python cryptography engine.

Verification & Status

Tested and verified against Hyperledger Fabric environments. Compatible with Python 3.10+ with cryptographic identity management, code integrity hashing, and token-bucket rate limiting.

Author: William Steve Rodríguez Villamizar (Wisrovi)

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