ABLOC: Accountable Blockchain Logging for Offline Care




Krysl, Joseph

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Retroactive security is important to cyber security; it is used to hold people account- able for their actions [1]. In the medical world, it is difficult to assign proper privileges, as they can be too wide and vulnerable to misuse, or too narrow [1, 2, 3, 4] restricting access to patient data [2, 4]. Clinicians are often given wide privileges to ensure they can access the data required to care for patients [2]. Logging is relied upon to find breaches of policies [2, 3, 4, 5] but, without reliable logs, changes can be made to the data in the EMR without anyone knowing [6]. Blockchain-based logging has been proposed but requires a stable internet connection [7]. This thesis presents Account- able Blockchain Logging for Offline Care (ABLOC), a Directed Acyclic Graph (DAG) based blockchain, that is combined with a gossip protocol to improve the forensic re- liability and accountability of logs. ABLOC can tolerate participating realms, the internet space that houses one or multiple pieces of medical software, going offline, recovering, and resynchronizing with the rest of the network. The ABLOC system receives log hashes, summarizes them, and shares the summary with different realms on the ABLOC network. This work presents the necessary background information, discusses the design of the ABLOC system, and evaluates the proposed system the- oretically and with a prototype. The proposed system has promising results in the scalability tests performed.



Blockchain, Logging, Electronic Medical Record, Forensic, Blockchain logging, EMR, EMR logging, Offline tolerant blockchain, gossip protocol, peer to peer, DAG Blockchain, Directed Acyclic Graph