Data Block Matrix and Hyperledger Implementation: Extending Distributed Ledger Technology for Privacy Requirements

Distributed ledger technology (DLT), including blockchain, has a number of properties that make it useful for distributed systems. However, the immutability of blockchain and most forms of DLT make it impossible to delete data, as is required for compliance with many privacy rules regarding personally identifiable information. Thus, there is a need for DLT that can provide the integrity-preserving property of DLT while also allowing support for privacy rules. The data block matrix (DBM) is a variant of distributed ledger technology. It provides the integrity assurance of blockchain but allows for controlled revision or deletion of data. This property is essential for using DLT in applications that must guarantee privacy requirements by the deleting of a user’s private data at their request. The DBM design solves the blockchain privacy conflict thus expanding the range of blockchain applications by also allowing exception management. It has been implemented and is available (https://csrc.nist.gov/projects/redactable-distributed-ledger) as a configurable option for Hyperledger Fabric (HF), with a proof-of-concept application for data sharing in a health care environment. Other potential applications include logistics management and digital currency. This paper will cover the DBM properties and data structure, the DBM implementation in HF, and a use case and application design of the DBM implementation using the pharmaceutical industry supply chain.