Eliminate replay attacks: Payload hashing & TTL validation in Fabric.

Replay attacks can lead to significant financial losses in financial and supply chain blockchains. To combat this threat, the wFabricSecurity Open-Source Engineering Series introduces a solution that employs payload hashing and Time-To-Live (TTL) validation.

Malicious actors can intercept valid signed transactions and replay them hours later, causing chaos. Additionally, bit-flip corruption during network transmission often goes unnoticed by application layers, while zombie transactions linger in network buffers and execute out of order.

The wFabricSecurity library provides a simple yet effective way to eliminate these issues. To use it, first import the library and create a security object. Then, create a message with a 60-second TTL:

msg = security.create_message(recipient = CN=EndorsementPeer, content = {tx_type : transfer, amount : 5000}, ttl_seconds = 60)

Verification checks for both hash integrity and timestamp expiration:

is_valid = security.verify_message(msg)

If the 60 seconds have elapsed, it raises a MessageIntegrityError, indicating that the message has expired. This architecture ensures that messages are time-bound, payloads are hashed for integrity, and replay attacks are prevented. The library is tested and verified against Hyperledger Fabric environments and is compatible with Python 3.10+. For more information, visit the GitHub repository (https://github.com/wisrovi/wFabricSecurity) or the PyPI page (https://pypi.org/project/wFabricSecurity).