1. Substack Downloads a copy of the original document
2. Substack Backs up the original document
3. Substack creates a Digital Fingerprint of the original and save the fingerprintDigital fingerprinting enables writers to verify that a  mirrored copy of the original or a confidential informant’s copy of the original document is authentic..
4. In the event of DMCA Takedown:

Investigative readers/reporters could search for mirrored copies and verify that the claimed document’s fingerprint matches the published digital fingerprint.

• The fingerprint could also be backed up by archive.org, building trust that finger print is authentic.
• Archive.org and Substack could continue to publish the original document’s digital fingerprint, even after a DMCA. takedown notice.