Sometimes you want to share a PDF with someone, yet hide some of the information. For example, you may need to provide a bank statement to someone to prove you have a bank account, but not want to show the balance.
There are a number of ways you can do this, and one way that has been common for many people is using apps to pixelate the text you want to hide. But a security researcher has shown that this sort of pixelization is reversible.
Fortunately, if you use a Mac, you have access to a much more powerful redaction tool in Preview, the app you can use for viewing PDFs and images.
Read the rest of the article on The Mac Security Blog.
Thanks for this Kirk. I looked up your instructions again last night because I could not find the redact button anywhere. The answer is: make sure it is a PDF you are editing.
I had taken a screen shot of a bank statement then opened it in Preview to redact the private data. But the file was a PNG so the redact button was not shown. Took me a while to realise what was the problem.
I noticed some comments on your Mac Security Blog article also saying they could not find the redact button, so maybe they had the same problem.