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A tool for recovering passwords from pixelized screenshots

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11–20 of 130 posts

Re: A tool for recovering passwords from pixelized screenshots

#12
post #3

Why is pixelation preferable to a big black obliterating box? To me, it seems like a lot of wasted time and effort and potential arms race between encoders and decoders and the risk of being exposed when you could just put a big black box over whatever you wish to obscure.

It's not. There's never going to be a tool that does this with black bars. The only benefit I can think of is legitimacy. Having something blurred there suggests that there was actually something there.

Black bars alone may still leak info.

First, if you add black bars on your own and don't use professional redaction features of software, you might miss the OCR text layer of the PDF, or the bar might be added as a separate object entirely which means it can also be removed later on.

Second, if you don't use monospace text, the width of the text you are redacting will reveal information about it. That's why monospace fonts are so commonly used in the intelligence community for example.

Third, if you just add a black bar to a screenshot, there might be residual values of the text left in adjacent seemingly white portions of the image, but they might not be entirely white due to compression effects. Better you run it through a filter before publishing.

Re: A tool for recovering passwords from pixelized screenshots

#14
post #4

Is "pixelized" the norm somewhere? I'm used to "pixelated."

The way I use them, "pixelated" refers to images rendered to a target resolution in pixels. "Pixelized" refers to an image that is transformed to resemble pixel art of lower quality (in terms of resolution and color depth).

A screen from Super Mario Bros is pixelated. That's what the art is supposed to look like.

A screen from Broken Age running in Retro Mode is pixelized. The art isn't actually intended to look like that, and it's just for nostalgic effect.

Re: A tool for recovering passwords from pixelized screenshots

#15
post #13

Relatedly (and this is probably not surprising to anyone here) if you draw a black box on a PDF file to cover sensitive information, chances are a simple screen reader will still able to extract the information just fine.

Redact ---> print ---> scan ---> distribute.

I think US courts and lawyers are finally starting to learn this.

Re: A tool for recovering passwords from pixelized screenshots

#16
post #13

Relatedly (and this is probably not surprising to anyone here) if you draw a black box on a PDF file to cover sensitive information, chances are a simple screen reader will still able to extract the information just fine.

That's why you always use the Adobe Acrobat Redaction tool. It'll obliterate everything and the metadata too!

Re: A tool for recovering passwords from pixelized screenshots

#17
post #3

Why is pixelation preferable to a big black obliterating box? To me, it seems like a lot of wasted time and effort and potential arms race between encoders and decoders and the risk of being exposed when you could just put a big black box over whatever you wish to obscure.

It's not. There's never going to be a tool that does this with black bars. The only benefit I can think of is legitimacy. Having something blurred there suggests that there was actually something there.

There is still a risk to leak the length of the password. If the font is known and the size of the rendered text can be inferred that would limit the search space considerably.

Re: A tool for recovering passwords from pixelized screenshots

#19
post #17
post #3

Earlier quoted context omitted.

It's not. There's never going to be a tool that does this with black bars. The only benefit I can think of is legitimacy. Having something blurred there suggests that there was actually something there.

There is still a risk to leak the length of the password. If the font is known and the size of the rendered text can be inferred that would limit the search space considerably.

Personal Snippet, if I want to hide/cross something I wrote on paper, I usually change letters to something else, like u to g, i to d, nothing preplanned, whatever comes in mind, before I cross line the text in forward slashes, backword slashes, & in horizontal lines.
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