After correctly redacting the text passages on the PDF page, the PDF's bookmarks referring to redacted content were overlooked. The confidential information was removed from the page as intended - but was unfortunately disclosed in the PDF bookmarks!
See the Spiegel Online article (in German) from January 29th, 2021: "That is in the redacted passages of the AstraZeneca contract. The EU Commission apparently made a serious glitch when it published the vaccine contract with AstraZeneca: Parts of redacted passages are legible - and contain some interesting information."
It is always critical when confidential information gets into the public and / or the wrong hands. The fact that the page was redacted correctly in this case does not release you from your obligation to review other PDF objects.
Comprehensive PDF redaction covers the following areas:
If you lack appropriate redaction software it's possible to print the redacted PDF, scan it and run text recognition over the new PDF document before distribution.
There are a variety of solutions for content redaction; see the redaction category in the PDF Association's Product Index. In addition to anonymization, pseudonymization may also be required, in which case each redaction is marked by codes indicating the purpose of the redaction.
Michael Karbe is Managing Director of Actino Software and has been a member of the PDF Association since its founding in 2006. His company supports organizations and institutions in digitizing processes using PDF. Through sales and development of a wide variety of applications, Actino Software is very familiar with the specific requirements and has recently launched the pdf Forensics Lab …