Illicit Cryotocurrency Investigation Digital Forensic Framework: Integrating Off-chain and On-Chain Analysis for Two Types of Crime

Cryptocurrencies have emerged as integral components of modern financial ecosystems, yet their pseudonymous nature poses significant challenges for digital crime investigations. This study proposes the Illicit Cryptocurrency Investigation Digital Forensic Framework, a novel model that integrates both on-chain and off-chain forensic techniques into a cohesive investigative process. Unlike prior research that treats blockchain analysis and conventional digital forensics separately, this framework combines blockchain transparency with contextual digital artifacts to form a unified approach. Validated by expert judgement from digital forensic practitioners, the framework is designed to address two primary crime scenarios: Type A, where investigations begin with suspect-owned devices; and Type B, where blockchain transactions provide the first investigative lead. The framework’s structured process—from identification to reporting—ensures evidentiary integrity, traceability, and legal admissibility. Beyond its practical application, the study lays groundwork for future developments, including the integration of artificial intelligence and cross-border legal interoperability in cryptocurrency-related crime investigations