Digital forensic in IoT paradigm: Blockchain assisted digital forensic framework with improved cryptosystem

Recent investigative frame works, digital forensic tools, and techniques are incapable of acquiring the IoT paradigm's dispersion and heterogeneity characteristics that make law enforcement organizations and digital forensic investigators do their tasks. To address these issues, this study presents a Blockchain-assisted digital forensic system for the IoT context. The devices in the perception layer contain several forensic evidences, which are transmitted to the further layer called the Fog layer. Moreover, the secure transmission of messages from the perception layer to the fog layer is a major challenge. To address this issue, the user's identity (investigators and devices) can be mapped to a pseudo-identity and the security of signature and confidentiality mechanisms ensures both privacy and security. Subsequently, the Fog layer verifies the signature data and employs an improved Blowfish encryption algorithm to provide security to the evidence transmission. In order to encrypt the evidence, the optimal key is generated using the SSAJO algorithm. Then the encrypted message is subjected to a distributed ledger called consortium blockchain that improves the security factors with a greater level of control. Moreover, the proposed IoT framework controls the cloud locally to store, and access data, and performs occasional synchronization with a consortium blockchain.