Why blurring sensitive information is a bad idea (2007)
dheera.net
dheera.net
Police took a photo with a "swirl" effect of a paedophiles face and reversed it to reveal a very usable picture. So good in fact he was found and arrested.
A phrase I never thought I'd see.
A child molester is someone who actually engages in inappropriate sexual activity with a child.
A child molester may or may not be a pedophile, for what it's worth (one may molest a child for reasons other than sexual attraction - even when you look at rape of adults, in many/most cases sexual attraction is not the primary motivation of the rapist[0]).
More on topic about censoring important information. I'm not entirely sure about this, but I feel like I've seen images where the thumbnail was retained from a previous version. Even at 32x32 there might be some way to expand it and gather some kind of information from its pixelated form even after the actual image was censored.
I'm sure you meant something about the proclivity to commit rape or molestation, but all this statement does is say there is a positive correlation between the two groups (and no citation or explanation of reasoning either).
Your statement would still be true if both groups had a large increase in probability of rape or molestation, vs the non-homosexual and/or non-pedophile.
Maybe not very much more likely, but it's definitely not less, and probably not equal.
Agreed. Sadly, society (like many in this thread) would rather create an environment where people like that cannot get help. Rather, they must stay repressed, stay isolated, and further the likely hood of uncontrollable behavior.
Rehabilitation is something most don't want to discuss these days. God help those who lose the genetic lottery.
I think the point here was that [and I could be wrong] we shouldn't assume pedophile == child molester because pedophilia is currently classified as a mental disorder but more importantly, as a sexual attraction to prepubescent children which does not in any way indicate a tendency to cause harm. For all you know, in 60 years, we might start seeing moves to accept pedophilia as a socially acceptable sexual orientation as we did we homosexuality. Let's not forget the dark history of homosexuality's acceptance into society too soon as traces still linger even today
Again, purely logical statement and not intended to insult.
It's generally deemed a socially unacceptable orientation, just as homosexuality was in many societies until only recently, but it's an orientation nonetheless. It's a useful metaphor with a lot of parallels to be drawn.
In any case, the parent comment was only using the metaphor to illustrate an important point; that being sexually attracted to a certain group of people, and actually molesting members of that group, are two wholly separate things.
Referring to someone convicted of molesting children using the term for someone who is merely sexually attracted to children is a significant misrepresentation.
http://www.washingtontimes.com/news/2013/oct/31/apa-correct-...
The APA are not the ultimate arbiters of what is and is not a sexual orientation, and if anything, the fact DSM-5 referred to it as a sexual orientation lends credence to the view that it is as such.
Sexual orientations and psychiatric disorders are not mutually exclusive.
Bear in mind for much of history society treated homosexuality akin to a psychiatric disorder (Edit: It was in fact classified as a mental illness in both the first and second editions of the DSM, released in 1952 and 1968, so let's not treat the DSM as gospel)
Please be clear that the article described the description of pedophilia as a sexual orientation in the DSM was an error - not a mind-changing. There was no "credence" lent to it being viewed as such; it was mistake and was admitted as such, and corrected. It was intended to read "sexual interest", not sexual orientation.
“In fact, APA considers pedophilic disorder a ‘paraphilia,’ not a ‘sexual orientation.’ This error will be corrected in the electronic version of DSM-5 and the next printing of the manual,” the organization said. The error appeared on page 698, said a spokeswoman.
The fluidity of the APA DSM is not something that is worth arguing; we can all agree that definitions change and have changed. I'm operating under the current set of definitions and primarily wanted to make the point that likening paraphilic disorders as "sexual orientations" is typically hurtful for reasons that probably don't require explaining.
> According to the DSM-5, pedophilia “refers to a sexual orientation or profession of sexual preference devoid of consummation, whereas pedophilic disorder is defined as a compulsion and is used in reference to individuals who act on their sexuality,” NeonTommy wrote.
Basically, the term that they use in the DSM is "pedophilic disorder" (changed from "Pedophilia"), which is a classified disorder.
Rather than creating an environment where someone with desires (that they cannot control, mind you) must hide and isolate themselves, rather than Getting help!
You realize that you're only making pedophiles more likely to harm children right? They need help, not damnation.
A pedophile is much more likely to molest a child, because that's the only way their desires can be realized in the physical world. A homosexual could, I dunno, go have consensual gay sex? That's why people find this comparison offensive.
(To clarify, I absolutely to not condone any interactions whatsoever to do with pedophilia... but come on, people, let's not be blind here to the existence of people with full self control, ethical behavior, and private thoughts and desires.)
Completely agree. Sad to think that there are people out there that have done nothing wrong, and cannot control their desires, and yet people (like many in this thread) would judge them without a second thought.
Lets hope none of them commit adultery by simply desiring another person. /s
Western law currently says no. But allowed sexual behavior (especially in this area) has historically been all over the map. One or two generations ago we were castrating homosexuals for their unnatural bevahior. Pederasty was an important part of Greek culture. Research the age of consent around the world and prepare for surprises.
I'll agree that a pedophile is much more likely to molest child, though. We define it that way.
A few times, we'd end up with a 32x32 pixel image that was 20 megabytes in size - because that metadata included the original image.
Well, unless we've started prosecuting thought-crime. I could have missed that update.
"But officer, I was only shuffling bits!" isn't a defense.
Or how about classified information. Is it thought crime to have classified information you aren't allowed to have? "But it's only bits, how can bits be illegal?"
Previous discussion: https://news.ycombinator.com/item?id=1939607
A bit more precise this post is even older, and was first discussed in 2007 prominently in these two places: http://www.reddit.com/comments/xaae/how_to_extract_personal_...
https://www.schneier.com/blog/archives/2007/01/how_to_recove...
(please refrain from responding with XKCD references, I'm aware of that, just want to link to older discussions)
> WHAT... why would you completely black out the number, where you could instead use random coloured squares, that look like it is a blurring, so someone can go through all the effort, decoding your white noise, and thinking in the end they have your number... when they don't ;)
http://it.slashdot.org/story/07/01/07/1352242/blurring-image...
Not sure what prompted someone to repost it to HN today. But that's cool because I see people continue doing this on a daily basis.
I think I once saw that on the site of a home security company, citing an email from customers who thanked them for burglarproofing their home in XX XXXXXXXX Street. Quite ironic.
The best solution was to actually cut out the parts of the page you don't want seen and then scan in the result. All other methods are prone to mistakes.
Edit: corrected link to segment http://www.msnbc.com/rachel-maddow-show/watch/redaction-rule...
See also: http://u88.n24.queensu.ca/exiftool/forum/index.php?topic=451...
Additionally, depending on the type of information you are trying to recover, you may already know the number of characters (for example, a US SSN), in which case fixed-width typefaces mean you get no information you didn't already have, whereas a proportional one would at least give you a little bit of info. But on the other hard I would also guess fixed-length strings such as an SSN are more likely to appear in a more "table"-like part of a document than in the middle of a paragraph of text.
I suspect it'd still be a bloody hard analysis either way, but at least according to this back-of-the-envelope theory a proportional typeface should preserve more information.
From the Le Monde article: The space occupied by an "I" differs from that taken by "W," which can give additional clues, compared to the text-spacing known as "monospace," like that of often used in e-mailwhere all the letters have the same spacing.
From the NYT article: In January, the State Department required that its documents use a more modern font, Times New Roman, instead of Courier, Mr. Naccache said. Because Courier is a monospace font, in which all letters are of the same width, it is harder to decipher with the computer technique. There is no indication that the State Department knew that.
Not really. OCR is plenty good enough to scan a document and then you can just replace anything you wanted redacted with a common string: [REDACTED]
Even if OCR wasn't an option, it would still (probably) be easier to type up the document than it would be to physically cut out all the things you want to redact.
It's a little easter egg for the people with an unblur plugin.
Using a 'smear' brush would be a more secure way to blur, there are various sizes and you introduce some randomness in the path of your mouse/stylus when blurring, and you can go over the numbers multiple times. Blurring to much higher factors is a better idea but it is simpler to just use black bars.
If you blur tool is of the variety that doesn't conserve total brightness, such as most "smudge" tools, and you use human randomness to blur it, then it would probably be pretty hard to reverse.
I still recommend cutting out the sensitive information rather than blurring it, just to be safe. Also, leave a generous margin, (1) to avoid giving information about length, and (2) because lossy compressors may have left tiny artifacts of the sensitive information in the areas around it.
If you want that pixel mosaic look for extra futuristic feel, remove the original content by making it fade into background, replace with new, irrelevant content, and then pixelize.
Other documents provide their own context - they have a lot of other text - that you can use to get font, font size and spacing and etc.
Also, doesn't adding a black bar on top of a text means just adding more bytes to the file, instead of removing the bytes belonging to the now hidden text?
The results won't be perfect, but they are usually close enough to see much of the detail that appeared to be lost.
I never use blur to obscure sensitive information; black that shit out (and then also make sure you aren't saving it as metadata or in a layer) or just replace it with fake data.
If you have a photograph of me, and I just let my hair and beard grow for a month, then you won't match the mosaic version of my hairy version with the old photograph.
Perhaps you can add some filters to adapt the contrast, luminosity, hue, illumination, rotation, pixel shifts and noise. It would be more difficult to fix the head orientation, open/close mouth/eyes.
Then futuristic analysis software that, from a picture, can determine all the light-sources in that image and 3D positions thereof.
So take a photo, analyze it for light-sources, then brute-force it by applying 3D models of every face in your database with the known light-sources and run it through the mosaic filter.
Futuristic technology could help here. Probably wouldn't work since I'm sure one person's mosaic would match too closely somebody with similar features and a similarly-shaped head.
They advise you not to blur, yet require blurring for comfortable reading? How ironic!
any number of very obvious methods can be used to avoid this besides using a black box...
Gaussian blur suffers from exactly the same problem, although a different difference function is needed for it.
> You think the technique mentioned in the article doesn't leak data?
Not that it matters now, but I always assumed blurring distorted the data in way way that would make it hard to recover in practice.
This blew my mind, https://www.youtube.com/watch?v=tyHBnT4PmTE