NIST is releasing a draft white paper, A Data Structure for Integrity Protection with Erasure Capability, for public comment. It describes a data structure—which can be referred to as a “block matrix”—that supports the ongoing addition of hash-linked records while also allowing the deletion of arbitrary records, preserving hash-based integrity assurance that other blocks are unchanged.  The block matrix data structure may have utility in applications requiring integrity protection that currently use permissioned blockchains. This capability could, for example, be useful in meeting privacy requirements such as the European Union General Data Protection Regulation (GDPR), which requires that organizations make it possible to delete all information related to an individual, at that person's request.

The public comment period is open until August 3, 2018.