225

As mentioned in the answers to a very similar question, scribbling over part of an image will destroy the original pixels, assuming that your editor doesn't store any layers or undo history in the saved image. (Paint doesn't.) There are some things to watch out for, though: The width of the blanked region places an upper bound on the length of the secret ...


190

Yes, it can be recovered. As long as shutter does not use layer (it almost certainly does not) and as long as the black is really all black (it must not be transparent), it is enough. The picture that you provided uses some amount of transparency, see here: All I had to do is use the Fill tool in MS Paint. If I used some algorithm that would take the jpg ...


157

Short answer: It's an artifact of Nikon Picture Project I had difficulty finding "Nikon Picture Project" but finally found a 1.5 version to try. The last version produced was 1.7.6 . It turns out that "Nikon Picture Project" does indeed implement non-destructive editing with undo and versioning capabilities. Unlike every other photo editing software I've ...


79

You don't even need to use an image editor in this case to recover the "redacted" text. Simply zooming in on the image is enough to read it. So I would say that yes, it most certainly is possible to recover the original text.


70

In this case the image can be recovered very well As others already pointed out the dark patch is not completely black. It has a transparent effect and only darkens the original image. The original image can be recovered almost completely: In this case the recovery was pretty straightforward. I needed to check the range of grey levels of the patch and re-...


64

Ditto Ben N, but let me add a couple of points that are too long to fit as comments. I'd emphasize the distinction between layered and un-layered data formats. Drawing a black box over a section of a GIF, JPG, or PNG image destroys the previous contents. Drawing a black box over a section of a Photoshop, Corel Draw, or Paint Shop Pro native image does not ...


62

Is a password-protected stolen laptop safe? No. The immutable laws of security say: Law #3: If a bad guy has unrestricted physical access to your computer, it's not your computer anymore. It doesn't matter if your laptop is password-protected or not. As long as the disk is not encrypted by a state-of-the-art encryption algorithm, anyone can access your ...


46

Normally, I'd just parrot the "nuke it from orbit and start from the beginning" line. However, information security is also about understanding your adversary, the practical risk, and the assets you're trying to protect. In this case, I think situation is a bit different; your spouse clearly just Googled for "free key logger" and downloaded the first one or ...


45

Change all your passwords! (no one had mentioned this) This is assuming that you're going to take an open approach to this problem rather than engage in counter-spying or image manipulation of your own. It's fairly basic advice, but do this on a computer you trust (this one cleaned or at work), and don't re-use any of your old passwords. Personally, I like ...


45

Usually the PNG format does not support multiple layers. So when you draw over something, whatever was there before is lost. However, the PNG format supports storage of an unlimited amount of metadata which is usually not displayed by image viewers. This feature is often used by image editors to add additional metadata to the image. One possible use-case is ...


45

No, NTFS is not encrypted by default. can data be read straight from the sectors in clear text? Yes, by default NTFS files are unencrypted. Since NTFS 3.0, EFS (Encrypting File System) is a feature of NTFS, but By default, no files are encrypted, but encryption can be enabled by users on a per-file, per-directory, or per-drive basis.


45

This was less interesting than it seemed at first. The user might just have a broken camera, broken memory card, or malfunctioning photo editing software that fails to save the full resolution image, but is able to save various size of working thumbnails, including the 435 × 652 "original" picture. The filesize of your example picture is explained by a 4032 ...


39

This depends a lot on what medium is used to store the data and what you consider "irrecoverable". "Deleting" data mostly does not what most people think it does. Simply put, after a standard deletion, the data isn't gone but only the link between "Data XY lies at 0x000000" and the actual storage location 0x000000 is being deleted. Your data is still at ...


38

If you are in a crowd and you wear a mask, but nobody else in the crowd does, then you tend to attract attention... If you want to remain anonymous, then you must use only tools which do not single you out as a potential miscreant, i.e. tools that everybody uses. A good example is when you pay in cash: this is a mostly traceless payment system, and yet ...


38

Because normal read operation on a disk presenting error (physical or logical) may cause data corruption, destruction and even writing to recover bad blocks. You have to keep in mind that even the read operation may lead to physical damage or data modification.


29

Yes, the text can be unmasked, either by simply zooming in or using any of the techniques - but not restricted to - pointed by pabouk and Peter answers. I have clearly asked for the correct/most secure way of producing photographic evidence. Completely remove any sensitive data from print-screens. Steps Press the PRT SCR button on your keyboard (...


28

As other commenters have mentioned, the file contains data from Nikon Picture Project. What if you couldn't run that software, but you still wanted to know what was hidden inside? Nikon's Picture Project format seems to be entirely undocumented, which is no surprise given that it's a custom format for a particular app and was never designed for interchange. ...


25

It depends on how smart the thief is. We work with police to catch criminals based on their IP address on a regular basis. We've got a high success rate, but we can't catch them all. Usually, the IP address is enough to trace the connection back to the ISP (Internet Service Provider). Generally, ISPs will work with law enforcement in cased of known fraud ...


22

When blacking out sensitive information in Paint the original pixels are destroyed. But using Inkscape to black out part of a vector image does not destroy the pixels, but instead covers them. If someone removes the black cover they can see the pixels. The same applies to things like Foxit Reader (I almost sent a document with sensitive information which had ...


21

Just to add a very simple answer here, I regularly boot a linux live cd/usb on friends' computers who have done something weird and need to recover files, and simply copy them over to an external harddisk. This is standard procedure, nothing 'hacky' about it. So no, if someone was left alone with your computer, a windows password is trivial protection ...


20

The only reliable evidence of an internal person attacking your systems is if you catch them with their fingers on the keyboard. People often suspect insiders because they have spent an extraordinary amount of money building extremely sophisticated defenses, and they simply cannot imagine a hacker being able to navigate them. They have grandiose releasing ...


19

1: The ISP only knows the MAC addresses for the address of the hotel's router. It may store that, but who cares. The hotel could store mac addresses for connected devices, and many do for captive portal use, but that history is typically forgotten after only a couple of days. The only way to know is to ask the hotel. (they probably won't know how to access ...


18

Have you seen the Tor document on how a Tor Hidden Service works? Essentially, in the same way that it's hard to find the source of traffic from a Tor exit node, it's hard to find the server operating a Tor Hidden Service. Authorities can't shut down the server, because they can't find out where it is. The .onion TLD is not really a TLD (so there is no ...


17

As a raster image program that does not use layers nor contain an undo history after saving, overwriting sensitive pixels in Paint irrevocably changes them in the saved image. More reasoning: Microsoft Paint is a proven simple piece of software with a long history and great popularity that works natively in simple raster image file formats. Serious flaws ...


17

It's not corrupt, it's just filled with APP10 segments, containing some sort of application specific data. Nikon-specific probably, because there are Nikon-references in the APP1/EXIF segment at the start. And after about 6 MB of APP10 segments, there's 103,001 bytes of actual JPEG image data. But all the segment markers are in the right place, meaning they ...


16

Like many others mentioned, there are trust issues here. thats needs sorting. the best way is a face to face discussion. an even better way to invite her is by typing out the invitation on your computer so that she sees your invitation and also comes to know of the keylogger in there. Now that you know your laptop is insecure, you should setup some admin ...


15

I essentially agree - using Tor from within Harvard's own WiFi network was a big mistake. Note that in this case, the perpetrator did not have the nerve to stay silent in the face of police questioning. His confession is what made the case against him airtight. Had he "lawyered" up, the police would have: Evidence that he used Tor around the time the ...


14

Disclaimer The approach I am about to describe might be unethical and perhaps even illegal. I am posting this for two main reasons: one I have no emotional attachment to your relationship; and two, because I like solving problems, the answer below is from a technical point of view: I am not really suggesting you do as I say below - the other answers that ...


14

Experts are experts. What an expert says stands in court as long as: He is an expert. The other party cannot provide another expert, who says that the first expert is wrong, and says it in a more convincingly expertish way. In practice, a email will be reputed to have been sent from a given PC if the context makes it a lot more plausible than any ...


14

As someone who runs personal honeypots and used to defend a massive global corporation, I can tell you that any attack leaves fingerprints. Styles of commands or command sequence, coding style of malware, as well as the paths used by attackers can all point in a direction of an attacker. For example, I was able to positively identify someone trapped in my ...


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