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Confidential Data Not Safe On Solid State Disks
An anonymous reader writes "I always thought that the SSD was a questionable place to store private data. These researchers at UCSD's Non-Volatile Systems Laboratory have torn apart SSDs and have found remnant data even after running several open source and commerical secure erase tools. They've also proposed some changes to SSDs that would make them more secure. Makes you think twice about storing data on SSDs — once you put it on, getting it off isn't so easy."
1 electric drill, 1 work bench, and some bored interns.
"Here Lies Philip J. Fry, named for his uncle, to carry on his spirit"
Encrypting it?
Is taking data off really an issue anyway. If it's confidential data, destroy the disk when you need to dispose of it. Not repurposing or re-selling hardware with sensitive information on it sounds like a no-brainer.
I know OCZ has its own wipe utility and I believe intel too. Using wiping software designed for mechanical disks makes absolutely no sense and the results from this study are 100% predictable. Oh your Gutmann wipe pattern for circa1991 MFM drives doesn't wipe SSDs? You don't say! If you needed to securely wipe one, use the proper tool.
That said, it would be nice if there was some standard way of doing this.
Thermite will fix everything! [s/fix/destroy] :-)
Did you mount a military-grade, variable-focus MASER on an unlicensed artificial intelligence?
encrypt the data before writing. at no point in its existence will it appear anything but white noise to unauthorized parties.
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
It's because the bits in the harddrive aren't actually binary but rather values that are intepreted as 1 or 0. For instance a value of 0.6 would be interpreted as 1 and 0.4 would be 0.
This means that if you look at the exact value rather then the interpretation you can make a guess at what values it has been before.
From what I've seen, it's not the end-of-life disposal of drives which leads to this type of data leak. It's when a drive dies under warranty and you send it to the manufacturer for a replacement. Since it's non-functional, you can't erase it. Since you need to return it without any signs of abuse for a warranty replacement, you can't destroy it.
The manufacturer usually just fixes it, and sells it as a refurb / sends it out as a replacement drive for others which have failed under warranty. They just do a quick format, or sometimes even don't bother formatting, before sending the fixed drive out. Meaning the new recipient of your old drive has all your data.
According to RTFA they can recover almost 100% of the data from a 0'd HD, 90% of the data from a randomed HD and 1-10% from a HD that has run extremely extensive random HD passes (Like Gutmann)
This is due to SDD's working differently then the standard HD's.
The lack of security of SSD's is not new! So unoriginal, in fact, that Truecrypt.org doesn't even recommend that you encrypt an SSD drive!
By scanning the surface of the platter with specialized equipment, it's possible to detect residual magnetization 'around' the area written by the drive head and determine where there used to be a bit. Actually using this technique to recover anything outside of a laboratory experiment (where the drive was only written to and erased with 0's once) is a myth, however. No one does this, not even CTU.
"Trust but verify"? Verification results from the exact opposite of "trust" :p You're right to verify, but saying stuff like that sounds silly..
Verification is after-the-fact. Prior to that, the vendor could still do something dishonest like fail to deliver on its promises. You're trusting them not to do that as indicated by your willingness to do business with them in the first place. Verification is an attempt to check against not only dishonesty on their part but also well-intentioned mistakes that wouldn't strictly be issues of trustworthiness.
It's sort of like when I deposit cash at a bank. If I tell them "this is 200 dollars, please put it into my account" they are going to count the money. I don't take that as an accusation that I am trying to deceive them, because it isn't. It's a standard practice because multiple pairs of eyes are more likely to catch both honest mistakes and deliberate deception. That's an example of "trust but verify".
It's not really so silly and it's far less extreme than "I want to be involved in each step of the process so I can watch your every move". That would be distrust.
It is a miracle that curiosity survives formal education. - Einstein
Essentially, residual magnetism and other sciency-bits.
Suffice it to say, simply writing a bunch of zeros doesn't erase all traces of what was on. With old school HDs, you needed to write random data to each location multiple times -- there's a DoD spec for doing it (DoD 5220.22-M).
I believe the article is saying that it doesn't seem to work with SSDs.
Lost at C:>. Found at C.
Or in a microwave. That seems to destroy the gates on the chip. 10 seconds on High should be enough. Just be sure to only place the PCB and not the entire drive as they can contain lots metal.
Life is not for the lazy.
I challenge anyone to find my MicroSD card. I've conducted extensive security audits to verify that no attacker, even one with inside information, can gain electronic or physical access to the disc.
Block storage devices have more capacity than they report. Magnetic disks keep a small reserve of unallocated blocks as a hedge against blocks that fail in use. SSDs keep a much larger reserve because they can only erase in increments that are relatively large compared to their block size.
If you overwrite a sector on a magnetic disk, you will almost always destroy all traces of the old data. The exception is when the drive thinks the old sector has failed or is about to fail, in which case you get an entirely new sector, and your old data is still (possibly) on the old sector. Attacks using magnetic force microscopes to read data from track fringes were possible a decade ago, but there is no reason to think it is possible on a modern drive.
If you overwrite a sector on a SSD, the SSD gives you a whole new block from a list of free blocks, and adds the address of the old block to the list of deleted blocks. Blocks are moved from the deleted list to the free list when the SSD has some free time, or when one is really needed. There is currently no mechanism to force the SSD to actually erase a sector.
This is all known, and there are mechanisms built into the specs to provide a secure erase. What their research is showing, however, is that these mechanisms don't always work. A number of them are buggy, and at least one just plain lies, claiming to have done the secure erase, but actually just doing the normal pointer update trick just like any other write.
See that "Preview" button?
You couldn't possibly seriously mean we should start reading the entrails? That is soo medieval.
It IS pretty much impossible, but that's not going to stop people from perpetuating the wive's tale for decades to come.
I actually have seen Magnetic Force Microscopy used as a tech demo to image the bits on a floppy disk. I asked the process owner if it could be used to extract data, and he just rolled his eyes. He said that besides the issues with modern hard drives having bits that are orders of magnitude smaller both in size and in magnetization, it's just impractical to extract any data, which should be obvious since it takes like 10 minutes to image a handful of bits. A handful of bits that could mean anything, and be anywhere on the disk platter, and anywhere in the file system, and which could represent erased or scrambled or encypted data anyway. I think the idea that you could go beyond even that and divine what bits were written "UNDER" the current ones is just fantasy. I have heard rumors that NSA has made purchases of a large quantity of scanning probe microscopes for this purpose, but they could have just been buying some for testing...manufacturing volume for scanning probe microscopes is such that an order of a half-dozen of them would be an overwhelmingly large order.
The most fun I ever had disposing of a HDD was when I worked as a mechanic. One of the POS systems was being replaced and the drive in it was going to be shredded. It was a slow day then, so I bugged our IT guy to let me have a crack at it. With an evil grin, I took it out to a workbench, stuffed it in a vice, and beat the piss out of the casing with a hammer. Once it was suitably mangled I started taking it apart with a prybar and screwdriver (gotta save those magnets!) until all I had left was the stack of platters. I took them to the 10 ton press in the back and squished it into a platter-pizza. Then I went to the corner and took the Oxyacetylene torch to that sum'bitch, entertaining myself by doodling molten penises and happy faces in it.
Best day at work EVAR.
TrueCrypt volume inside a TrueCrypt volume
You, dawg, I heard you liked TrueCrypt.
The headline should just read "Confidential data not safe on unencrypted disk". Modern hard drives also arean't as easy to 100% delete as one might think - once a sector gets "spared out" there's no easy way to delete it, and there will still be readible data there. That just happens a lot less frequently than SSD load/wear balancing.
Of course, any media can be adequetly destroyed by shredding - if you really care, this isn't a problem to solve with software.
Socialism: a lie told by totalitarians and believed by fools.
This is when you tell us he re-assembled it, loaded up some Linux Drive Recovery program and pulled all the data to safety, right?
-=This sig has nothing to do with my comment. Move along now=-
And what good is that?
Again, this is a SSD, not a hard disk. The PCB contains both the interface and the data storage parts. If you microwave that, you've destroyed everything that was important. It's no use to unsolder anything, the flash chips themselves are destroyed by microwaving.
The part you would skip on microwaving is the metal casing, which contains no data.