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It's helpful to understand a little bit of how a PDF file works. A PDF file stores a sequence of instructions for what do draw on a page. The instructions are
by cduan 17y ago
It's helpful to understand a little bit of how a PDF file works.
A PDF file stores a sequence of instructions for what do draw on a page. The instructions are commands, such as "write this text here" or "draw a circle there." When you draw black redaction boxes, you are just appending an instruction to the end of the list ("draw a box here"), but most of the time the previous instructions are all still there.
Really, the only way to redact a PDF with certainty, short of manually reading the file itself (yes, PDF files are text-readable; you just have to decompress them) is to rasterize the file to a large image. Otherwise, the instructions for writing the text are all still in the file, and there are any number of ways to extract them (for example, simply by deleting the instruction to draw the redaction box).
- anigbrowl 17y agoMrs Browl works at a e-discovery company where documents are often redacted depending on which bits are admissible in court; I gather they use TIFF files for exactly the reasons you describe. I suppose the (extremely limited) redaction features in Acrobat stem from the belief that the document is ultimately destined for printing rather than computer reading.
- pasbesoin 17y agoI have no personal experience and at best perhaps a vague recollection of having read or heard something, but would document images be or in the past have been used also to make discovery as inefficient as permitted for the opposition? Images require a person to analyze, or pre-processing before electronic search and analysis can be performed against them.
- anigbrowl 17y agoOCR is very good nowadays, so that's not so big a problem - and for big lawsuits (eg patent fights) there are literally hundreds of lawyers hired to comb through the vast array of documents deciding whether they're responsive or not. The pre-processing is largely automated but there's certainly a portion (maybe 5%?) of documents that need to be hand-classified in the database before they get to the lawyers. It an interesting field - lots of money to be made, intense competition for it, relatively simple technology requirements but a legal industry which has been resistant to technology for quite a long time. Autonomy seems to be the leading software company in this space.
- pmorici 17y agoI can't speak for their other products but in my experience their enterprise search product is a useless piece of crap.
- tedunangst 17y agoWhen you're billing the client $300 an hour to do a job they can't easily take elsewhere, you don't have a lot of incentive to improve efficiency.
- eli 17y agoI heard once that NSA guidelines are to print out PDFs, redact portions with a marker and then rescan them into new files.
- metachor 17y agoI also work at an e-discovery company and can confirm the use of TIFF files as the court-admissible format for producing any sort of document (especially if it has redactions). Here is an example of the process to apply redactions to a PDF file (or any sort of electronic document). The document is opened in a third-party native viewer with redaction capabilities (and not in the original application like Arcobat or Office). The end-user draws a black box over the appropriate text using the third-party native viewer. This redaction is saved as a separate layer that can be rendered on top of the native document when viewed in the software, as well as printed out. Finally, when documents need to be produced for court, they are printed out to a TIFF-printer driver, effectively converting them to TIFF and "burning in" the redaction layer. The TIFFs are delivered to the courts and opposing council.
- mschwar99 17y agoA government document can't (shouldn't) be rasterized because it would loose all the tagging information making it non-accessible in a 508 sense. It is however trivial for even a non-technically inclined person to remove the text content through Acrobat's content editing pane. Just as you suggest, things like this seem to be an example of someone in a large organization not quite understanding how the "magic" behind the tools they use work and winding up with results they didn't expect.
- weaksauce 17y agoI understand that but why would they not just replace the area with text that says [ redacted ] instead of the black box? Edit: you can pad the redacted box with spaces to keep the formatting consistent.
- derefr 17y agoPerhaps they want to keep the formatting, and don't want pages to reflow after they've already been layed out? The Unicode character "█" works well for this purpose.
- lt 17y agoI remember a similar story from a few years ago where redacted names where discovered from the length of the redacted characters. Turned out it wasn't too difficult to brute force names and see which ones matched the exact size of the redaction.
- eru 17y agoThey should have used a fixed width font.
- brown9-2 17y agoOccum's Razor: because "they" did not understand PDF and thought that they were making the text unreadable simply by drawing boxes over it.
- bia 17y agoIf you open the file in Adobe Acrobat Pro, there's a tool called "TouchUp Object" that lets you literally just click and delete the boxes.