But it takes a long time to securely delete data (Peter Gutmann makes a good case for ≥22 pass deletion and I concur. With a 160GB 7200 HD and a Sempron 2500+ 1.75 GHz processor, that takes… about a month.

So if and when I get rid of my computer, for ID theft reasons, I will never include the HD. I’ll destroy it with HCl (hydrochloric acid).

I know when I was in the military, magnetic media was shredded, then burned, period.

Christoph on November 17, 2006 at 1:18 AM

I kept it high level to prevent the distraction from all the nuances and bore the heck out of everyone.

I am not a “law enforcement expert”, but I have performed many data forensic examinations. My experience, generally, for an end user system, UNIX/Linux is no better than Windows in this particular matter.

Want sell the old computer at a yard sale? Overwrite the hard drive with a good tool using a good algorithm.

Really concerned with what is on the drive (bank accounts, SSN, credit card numbers, etc)? Toss it in a chipper (I think acid will make a mess and big hammers make little projectiles – wear goggles).

At a high level – Deleting data only removes some information on how to find the file. The data remains on the hard drive. There are many other variables, but generally, with continued typical use, over time, the odds are an analyst would find less, if anything, but you never know how much time is enough.

You’re right that the “odds” are less, but it depends on the operating system.

If Unix, the data tends to get overwritten (still recoverable by a law enforcement expert with the proper tools), but not in Windows, at least not anytime soon nor predictably:

Standing alone the DOS/Windows delete command simply does not ‘delete’ selected dat’s actual bytes from your disk/device. The DOS/Windows delete command only erases it’s own record of the area on the disk that your data occupied. Delete ‘unlinks’ the file by changing the first character of its name to a special byte.

Likewise UNIX and UNIX like Operating Systems standard delete commands do not completely wipe specified data unless specifically configured to do so. However, unlike DOS/Windows operating systems under UNIX like systems the area where the file resided on the hard disk drive is soon overwritten.

Laptops almost always use Windows, and even overwritten Unix is easily recoverable with the right tools.

The link that I gave above is the most concise guide to secure data deletion that I’ve seen (not the most comprehensive,.

Puritan1648 on November 16, 2006 at 11:03 PM

Emmett J. on November 16, 2006 at 11:15 PM

Human lives are in the balance and PC saps don’t want to play to win.

I would pulling every Mo and Fatima out of line for a brief conversation and closer proximity to my dog.

Is that a Koran in your bag? Wearing a hijab? An implosion device design in your back pocket? Print outs from a cyanide research project? Please step outside the rope rail.

When questioned, Dinssa responded, “I never sought that material. It comes as a pop-up when I visit fatwa-online.com.”

Wonder if they found a porn cache on his computer.

AZ_Redneck on November 17, 2006 at 12:42 AM

Chances are, if they did, it would be, “Jihadi’s Gone Wild!”

Usually fully deleting the files and defragmenting completely blasts away any trace of them.

At a high level – Deleting data only removes some information on how to find the file. The data remains on the hard drive. There are many other variables, but generally, with continued typical use, over time, the odds are an analyst would find less, if anything, but you never know how much time is enough.

And if there is anything left it will not be intelligible.

A good analyst can make the un-intelligible intelligible quickly, but the volume of the un-intelligble “stuff” can slow the analyst down when solving a puzzle.

Especially with encrypted data, which is often cross-related.

Depends. Strong encryption and an enlightened user, the analyst might be dead in the water. On the other hand, many “systems” are not as secure as folks might think. Analysts have “work arounds” (like those little pieces of paper with passwords on them that folks leave lying around).

You could just write 0’s to the whole drive (format it). Not gonna be 100%, but it will take some kind of clairvoyant to figure out what used to be on there.

Format it once a day, twice on Sunday – the data is still there and an analyst will find it. Using a good data overwriting technique might stop an analyst cold, but make sure all of it was overwritten.

Regarding the first question;

First, what sort of files about cyanide and nuclear materials are “normally” downloaded from the Internet?

When questioned, Dinssa responded, “I never sought that material. It comes as a pop-up when I visit fatwa-online.com.”

Wonder if they found a porn cache on his computer.

Customs officials became suspicious of Dinssa when a narcotics dog signaled the scent of drugs on the money in his possession.

I seem to recall reading that virtually all paper money in the U.S. has enough drug residue to cause a dog to alert. According to this article, found in a cursory web search:

For example, a high percentage of U.S. currency is contaminated with cocaine, so that a drug dog’s alert to cash is not persuasive evidence that the money is illegally obtained profit from the sale of narcotics. US v $506,231 in US Currency, 125 F3rd 442, 453 (7th Cir 1997).

Personally, I never travel without at least $75,000 in cash.

Peasant.

…this is what we’ve come to in these times, in this nation…you set out to find mass-murderers, and you’re cleared to do that — in fact, if you don’t do it in time, you’ll be excoriated! — but you cannot give offense. Puritan1648 on November 16, 2006 at 11:03 PM

The true Catch-22, isn’t it?

PC gone wild in a world gone nutty.

I say deploy the dogs everywhere. They don’t single people out because of their surname or the color of their skin. — Constantine

…this is what we’ve come to in these times, in this nation…you set out to find mass-murderers, and you’re cleared to do that — in fact, if you don’t do it in time, you’ll be excoriated! — but you cannot give offense.

How about the offense given to 80 year-old grandmothers who have to bend over and take off their shoes?

How about citizens, importuned so that these “citizens of the world”, some of whom either support or encourage jihadism, don’t feel picked on?

When you’re out to catch a villain, particularly one whose announced intention is murder, chaos and terror, you don’t stand on niceties.

I’d use dogs, alright…rottweilers….

I mean, crap. You could just write 0’s to the whole drive (format it). Not gonna be 100%, but it will take some kind of clairvoyant to figure out what used to be on there.

Heh… it’s just a wee bit more complicated than that. Which is to say, it’s a whole lot more complicated than that.

Cristoph: I think you were joking about the files sticking around?

Usually fully deleting the files and defragmenting completely blasts away any trace of them. And if there is anything left it will not be intelligible. Especially with encrypted data, which is often cross-related.

I mean, crap. You could just write 0’s to the whole drive (format it). Not gonna be 100%, but it will take some kind of clairvoyant to figure out what used to be on there.

Every single part of your post is wrong.

Maybe we should let this guy loose and sentence him to life in SF. THe SF lifestyle should be torture for any good jihadist.

SF … the new Abu Ghraib? Would make San Fran Nan the new General Janis? Might be worth it if it could her demoted!

Usually fully deleting the files and defragmenting completely blasts away any trace of them. And if there is anything left it will not be intelligible. Especially with encrypted data, which is often cross-related.

I mean, crap. You could just write 0’s to the whole drive (format it). Not gonna be 100%, but it will take some kind of clairvoyant to figure out what used to be on there.

… makes total sense, especially since Allahpundit has “normal” files about cyanide and nuclear materials downloaded from the Internet on his hard drive right now!

Christoph

You are saying that the information downloaded received the red flag because it went beyond the idle curiosity category?

I think it’s not the usual kinds of files found stored on harddrives and certainly warrants a thorough investigation, IMHO.

Of course, Topsecretk9, I’m just pointing out that it’s normal to download certain info on nuclear weopans and cyanide — everyone who’s reading this web page has info about nuclear weopans downloaded on their computer (your post, as an example).

I’m just saying the statement that…

“these aren’t “sort of files about cyanide and nuclear materials are “normally” downloaded from the Internet”

… makes total sense, especially since Allahpundit has “normal” files about cyanide and nuclear materials downloaded from the Internet on his hard drive right now!

Simple, anyone who ever looked at a webpage with nuclear information such as diagrams, specs, etc. You probably have. And here’s cyanide from World War 2 holocaust history.

That’s true, but when you consider:

…Anti-Taliban leaders in Kandahar revealed that the uranium and other materials, including cyanide, had been discovered in a tunnel complex beneath the former base near the city’s airport. The find was confirmed by American officials…

…The cache included low-grade uranium 238, which could be used to make a so-called “dirty bomb” if wrapped around a conventional explosive. It would spread radiation over a large area.

From wayback and this:

Dinssa had been flagged by Customs and Border Protection inspectors for further screening after agents received information from authorities abroad that Dinssa had been “acting very strangely,” Palmore said.

I think it’s not the usual kinds of files found stored on harddrives and certainly warrants a thorough investigation, IMHO.

And to do it with a high level of certainty such that law enforcement couldn’t find them… takes… weeks not days for a large hard drive.

Dinssa, described in court papers as unemployed, told agents he had spent the previous months in Nairobi and had tried to start a taxi business, Palmore said. Dinssa was traveling through Amsterdam and Detroit on his way to Phoenix, Palmore said. “He wasn’t very forthcoming.”

Dinssa had been flagged by Customs and Border Protection inspectors for further screening after agents received information from authorities abroad that Dinssa had been “acting very strangely,” Palmore said.

Inspectors found $78,883 on Dinssa and in his luggage — $60,000 more than Dinssa reported carrying when questioned by Customs agents, Keen wrote. A drug-sniffing dog smelled narcotics on the money, Keen added. No drugs were found, Palmore said.

Inspectors examined Dinssa’s computer after they noticed he did not have a power cord for it, which they considered unusual, Keen wrote. Inspectors found downloaded files about cyanide and nuclear materials, Keen wrote.

“When questioned about the materials on his laptop, Dinssa stated that he was interested in learning about cyanide and nuclear materials,” Keen wrote.

“There are a lot of missing pieces to the puzzle,” Palmore said.

Two exit questions for this one. First, what sort of files about cyanide and nuclear materials are “normally” downloaded from the Internet?

Simple, anyone who ever looked at a webpage with nuclear information such as diagrams, specs, etc. You probably have. And here’s cyanide from World War 2 holocaust history.

You don’t need to “right-click, save as” to “download” something… how do you think a webpage works?

All the info is stored on the hard drive in your computer in a temporary file.

I say deploy the dogs everywhere. They don’t single people out because of their surname or the color of their skin.

Implying any other effort by PEOPLE instead of dogs is COLORED by their surname or the color of their skin? Are you insinuating that our enforcement folks (lame as they may be under current circumstances) are no better than dogs?

I find your racist assumptions offensive, at best. Typical.