[2604.04211] LOCARD: An Agentic Framework for Blockchain Forensics

Computer Science > Cryptography and Security arXiv:2604.04211 (cs) [Submitted on 5 Apr 2026] Title:LOCARD: An Agentic Framework for Blockchain Forensics Authors:Xiaohang Yu, William Knottenbelt View a PDF of the paper titled LOCARD: An Agentic Framework for Blockchain Forensics, by Xiaohang Yu and 1 other authors View PDF HTML (experimental) Abstract:Blockchain forensics inherently involves dynamic and iterative investigations, while many existing approaches primarily model it through static inference pipelines. We propose a paradigm shift towards Agentic Blockchain Forensics (ABF), modeling forensic investigation as a sequential decision-making process. To instantiate this paradigm, we introduce LOCARD, the first agentic framework for blockchain forensics. LOCARD operationalizes this perspective through a Tri-Core Cognitive Architecture that decouples strategic planning, operational execution, and evaluative validation. Unlike generic LLM-based agents, it incorporates a Structured Belief State mechanism to enforce forensic rigor and guide exploration under explicit state constraints. To demonstrate the efficacy of the ABF paradigm, we apply LOCARD to the inherently complex domain of cross-chain transaction tracing. We introduce Thor25, a benchmark dataset comprising over 151k real-world cross-chain forensic records, and evaluate LOCARD on the Group-Transfer Tracing task for dismantling Sybil clusters. Validated against representative laundering sub-flows from the Bybit ha...