Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2023/06/redacting-documents-with-a-black-sharpie-doesnt-work.html
We have learned this lesson again:
As part of the FTC v. Microsoft hearing, Sony supplied a document from PlayStation chief Jim Ryan that includes redacted details on the margins Sony shares with publishers, its Call of Duty revenues, and even the cost of developing some of its games.
It looks like someone redacted the documents with a black Sharpie but when you scan them in, it’s easy to see some of the redactions. Oops.
I don’t particularly care about the redacted information, but it’s there in the article.
Post Syndicated from Bruce Schneier original https://www.schneier.com/blog/archives/2020/10/reverse-engineering-the-redactions-in-the-ghislaine-maxwell-deposition.html
Slate magazine was able to cleverly read the Ghislaine Maxwell deposition and reverse-engineer many of the redacted names.
We’ve long known that redacting is hard in the modern age, but most of the failures to date have been a result of not realizing that covering digital text with a black bar doesn’t always remove the text from the underlying digital file. As far as I know, this reverse-engineering technique is new.
EDITED TO ADD: A similar technique was used in 1991 to recover the Dead Sea Scrolls.
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