Scalable Log Auditing on Private Blockchains via Lightweight Log-Fork Prevention

Abstract

This work presents TxChecker, a secure logging system over a private blockchain with two salient features: 1) TxChecker prevents log forking attacks without trusting any external party other than the blockchain, 2) TxChecker achieves a low cost on log auditors that is proportional to the data being audited. TxChecker employs a novel scheme to map the misbehavior of forking logs to the double-spending transactions, which are invalidated by the underlying blockchain. In the TxChecker protocol, clients and the server in the domain infrastructure both attest to a history of concurrent operations and send blockchain transactions. A prototype of TxChecker is implemented in HyperLedger Fabric. Evaluation shows that TxChecker reduces the costs of log auditors significantly compared to replication-based log schemes.