Scrybe: A Blockchain Ledger for Clinical Trials Richard R. Brooks, K.C. Wang, Lu Yu and Jon Oakley Department of Electrical and Computer Engineering Clemson University Clemson, SC rrb,kwang,lyu,joakley@g.clemson.edu Anthony Skjellum SimCenter & Dept. of Computer Science and Engineering University of Tennessee at Chattanooga Chattanooga, USA tony-skjellum@utc.edu Jihad S. Obeid and Leslie Lenert Biomedical Informatics Center Medical University of South Carolina Charleston, SC jobeid,lenert@musc.edu Carl Worley Department of Computer Science and Software Engineering Auburn University, Auburn, AL crw0034@tigermail.auburn.edu Abstract—The recent popularity of cryptocurrencies has high- lighted the versatility and applications of a decentralized, pub- lic blockchain. Blockchains provide a data structure that can guarantee both the integrity and non-repudiation of data, as well as providing provenance pertaining to such data. Our novel Lightweight Mining (LWM) algorithm provides these guarantees with minimal resource requirements. Our approach to blockchain-based data provenance, paired with the LWM algorithm, provides the legal and ethical framework for auditors to validate clinical trials, expediting the research process, and saving lives and money in the process. Contributions of this paper include the following: we explain how to adapt and apply a novel, blockchain-based prove- nance system to enhance clinical trial data integrity and non- repudiation. We explain the key features of the Scrybe system that enable this outcome, and we describe resilience of the system to denial of service attacks and repudiation. We conclude that Scrybe can provide a system and method for secure data provenance for clinical trials, consistent with the legal and ethical requirements for the lifecycle management of such data. I. I NTRODUCTION The recent popularity of cryptocurrencies has highlighted the versatility and applications of a decentralized, public blockchain. Bitcoin is the most well-known of such currencies; importantly, the underlying data structure, blockchains, can be applied more broadly than simply to provide a virtual/digital currency. In particular, blockchains provide a data structure that can be used to guarantee integrity and non-repudiation of data, as well as maintaining provenance metadata for systems. Our novel Lightweight Mining (LWM) algorithm provides these guarantees with minimal resource requirements. The LWM algorithm departs from the resource-intensive (and time- consuming) verification approaches that cryptocurrencies, such as Bitcoin, use when expanding the blockchain [1]. Our approach to blockchain-based data provenance, paired with the LWM algorithm, provides the legal and ethical framework for auditors to validate clinical trials, expediting the research process, and saving lives and money in the process. The remainder of this paper is organized as follows. First, in Section II, we describe the problem statement. Next, in Section III, we summarize Scrybe, our novel blockchain- based provenance system. In Section IV, we consider security verification, focusing on data integrity, non-repudiation, and resilience of the Lightweight Mining (LWM) algorithm to distributed denial of service (DDoS) attacks. Finally, we conclude and mention future work in Section V. II. PROBLEM STATEMENT Clinical trials test new treatments and pharmaceuticals for countering pathologies. While all science must be performed professionally and be carefully recorded; it is particularly important to track data and documentation changes in clinical trials to satisfy research integrity and regulatory requirements. Each clinical trial requires a detailed protocol that is ap- proved by the relevant authorities. Once the protocol is in place, an appropriate population of patients is recruited and their consent forms are carefully recorded. A randomization process assigns some patients to a group that uses the proposed treatment, while others are assigned to a control group that receives a placebo. As the trial progresses, the patient population is treated and raw data is collected. The raw data can take many forms. It may comprise surveys, blood tests, clinical examinations, etc. Either during the treatment or at the end of the trial, the raw data is evaluated to justify the results of the given trial. It is essential that all information be carefully recorded and not be subject to tampering. Assuring data integrity and veracity enhances the rigor of clinical trials. This ensures the validity of outcomes in compliance with Part 11 of Title 21 of the Code of Federal Regulations required by the United States Food and Drug Administration. Designing trustworthy and reliable systems for managing electronic records along with electronic signatures remains a major challenge in conducting human subjects research.