Motivation : Clinical genome sequencing laboratories return reports containing clinical testing results, signed by an Board Certified clinical geneticist, to the ordering physician. This report is often a pdf, but can also be a physical paper copy or a structured data file. The reports are frequently modified and re-issued, due to changes in variant interpretation or clinical attributes. To precisely track report authenticity we developed ARBoR, an application for tracking the lineage of versioned clinical reports even when they are distributed as pdf or paper copies. ARBoR employs a modified blockchain approach and instead of relying on a computationally intensive consensus mechanism for determining authenticity, we allow supervised and digitally signed writes to an encrypted ledger, which is then exactly replicated to many clients.Results : ARBoR was implemented for clinical reporting in the HGSC-CL Clinical Laboratory, initially as part of the NIH's Electronic Medical Record and Genomics (eMERGE) project. To date we have issued 15,205 versioned clinical reports tracked by ARBoR. This system has provided us with a simple and tamper-proof mechanism for tracking clinical reports with a complicated update history.

Motivation Clinical genome sequencing laboratories return reports containing clinical testing results, signed by a board-certified clinical geneticist, to the ordering physician. This report is often a PDF, but can also be a paper copy or a structured data file. The reports are frequently modified and reissued due to changes in variant interpretation or clinical attributes. Materials and Methods To precisely track report authenticity, we developed ARBoR (Authenticated Resources in a Hashed Block Registry), an application for tracking the authenticity and lineage of versioned clinical reports even when they are distributed as PDF or paper copies. ARBoR tracks clinical reports as cryptographically signed hash blocks in an electronic ledger file, which is then exactly replicated to many clients. Results ARBoR was implemented for clinical reporting in the Human Genome Sequencing Center Clinical Laboratory, initially as part of the National Institute of Health's Electronic Medical Record and Genomics (eMERGE) project. Conclusions To date, we have issued 15 205 versioned clinical reports tracked by ARBoR. This system has provided us with a simple and tamper-proof mechanism for tracking clinical reports with a complicated update history.