On Tue, Feb 17, 2009 at 5:12 AM, Michal Hocko <mstsxfx@gmail.com> wrote:
> I'm also curious if there are any convenient ways to securely redact parts
> of a PDF without rasterizing the text.

I am not sure what do you mean by that? Example?

Here's an example of a heavily redacted document - http://www.webspores.com/wordpress/wp-content/uploads/aclu-v-ashcroft-redacted.jpg

Even old-fashioned marking pens can leak information through redaction - http://cryptome.info/0001/cia-decrypt.htm

PDF makes it easier to get redaction wrong.

Most methods for redacting PDF are along the lines of converting to TIFF, redacting, converting the TIFF image back to PDF. So much useful information is thrown away doing it that way. To convert back to text you'd need to OCR it.