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Data destruction is a technique of last resort. If you are planning to use a new storage device, you should use full disk encryption. This allows you to either destroy the encrypted master key or simply forget the password, effectively rendering all data unrecoverable, despite no data actually being wiped. Encryption is a solution for both solid state and ...


43

To quote the ISM (Australia's military standards for cyber security). Security Control: 0359; In flash memory media, a technique known as wear levelling ensures that writes are distributed evenly across each memory block. This feature necessitates flash memory being overwritten with a random pattern twice as this helps ensure that all memory blocks ...


22

Next time you're about to put sensitive data on a flash drive, consider encrypting it first! Strongly encrypted data is useless without the key, and if you securely erase the drive first, all that will be left is an occasional sector of such encrypted data surviving due to wear leveling. If you're still unsatisfied by this technique because there's a small ...


17

A quick check at amazon.com shows 64GB USB drives in non-designer cases go for about $20. Less if you buy in bulk. Since you want "quick and efficient" lets factor in the time needed to overwrite the drive at least twice, and maybe running a drive scanner to verify the erasure. And then remembering to do it each time. A quick check of homedepot.com shows a ...


13

Tl;dr: Because you can never trust all storage drives to securely wipe themselves, you must plan as if none of your drives can be securely wiped. Placing a dependency on the type of media is not the right way to approach the problem, because the technology is always evolving and changing, and you can never be in 100% control of all IT spend. Remember that ...


11

Given that the device is not a solid state drive, should a secure ATA erase still be performed? If you want to erase the data, you can use ATA Secure Erase. It is not meant only for solid state drives and works fine on spinning rust. It takes a lot longer than on SSDs because hard drives are less likely to support SED, which allows instant erasure by ...


7

It's not possible to make an "un-deletable" file, because formatting an SD card doesn't delete the file. Formatting the SD card removes the data structure that tells you that the file ever existed. Even if you were to use forensic tools to examine the SD card, the thief could simply overwrite the entire SD card with zeroes, random data or whatnot, and you ...


4

Yes, a HDD magnet is fine or any neodymium one and will destroy the data by sweeping such a powerful magnet across the surface of a disk. However, the reliability of such a procedure may vary. You can also build your eraser in a similar manner to making a head demagnetizer for tapes (which is pretty simple: insulated wire, nail and an input voltage source). ...


4

What you are seeing is a cached view of the previous partitions. If they appear to persist even after a wipe, this is a result of the kernel caching the last known partition table in memory. It does this because it does not expect the layout to change at runtime, so rather than re-read the table each time the partition layout is queried, it reads it once at ...


3

Like many modern smartphones, the iPhone uses flash storage. A flash memory cell has a limited number of rewrite cycles. Two things make data shredding on flash storage difficult: Wear balancing: the storage controller will automatically remap physical storage blocks to ensure that all storage cells are used equally. This also means that overwriting a file ...


3

Yes it is possible but not easy. If you can hack the SD microcontroller you can do that and much more. The theory was demonstrated back in 2014 at CCC event. https://media.ccc.de/v/30C3_-5294-en-_saal_1_-201312291400-_the_exploration_and_exploitation_of_an_sd_memory_card_-bunnie-_xobs The problem is that is hard and specific to the microcontroller the SD ...


3

Securely deleting data, otherwise known as “wiping” can be surprisingly difficult. Overwriting data even once with “cipher.exe”, or any other tool, makes the data effectively gone. The old bugaboos about multiple pass wipes being necessary to thwart magnetic force microscope recovery of partial track wipes is urban legend. It was theoretically possible back ...


2

As far as data security is concerned, the partitions are almost meaningless. If you're trying to prevent forensics from reading your data, then it won't matter. If you've run a proper multi-pass shredder over the data, then the partitions will only matter if you named them something telling. Addendum: I've obviously hit someone's sore spot by suggesting a ...


2

Any path could easily be something the user doesn't want to delete. The user should not run your tool on a folder if that folder should not be deleted. Probably it is enough to always warn "THIS WILL DELETE ALL FILES IN /path/given/by/user, ARE YOU SURE?" and then rely on the OS (either through file permissions or access controls like SELinux) to protect ...


2

For basic types, such as long or array, I can't think of a way remote execution could be achieved. With classes, there are many options beyond virtual table. For example a member class may have a virtual table. A shared pointer could also be used, as it contains a pointer to destructor function. Other more exotic cases such as a destructor calling a function ...


1

"Shred" isn't always as effective as you might think, since it relies on the assumption of in-place overwrites. Using a Solid State Drive (SSD) with TRIM function enabled will reliably remove deleted data, but sometimes there's a delay that can stretch out to many minutes before TRIM does its thing. None of the above approaches address alternate storage ...


1

Ideally you need a bulk degausser. Back in the day of cassette tapes you could get a bulk degausser for about $20. Alas, this is now a specialty item and runs around $100. Using something like a neodymium magnet waved around the surface will selectively damage portions, making it unreadable by normal efforts. You have to decide the threat level you're ...


1

The whole multipass overwrite is fundamentally an urban legend hold over from a disk technology that hasn't been in use for decades. Overwritten data (even once) is not recoverable, there is no tool to do it. That said, the real issue is being able to actually overwrite the data in the first place. It's fairly simple to accomplish if you're wiping the ...


1

If it's a recent Iphone, a factory reset should cover it; the storage is encrypted with a device specific key and a 'session' key. randomizing that key renders the information stored there inaccessible, irrespective of wear leveling concerns. https://www.howtogeek.com/339705/what-is-apples-secure-enclave-and-how-does-it-protect-my-iphone-or-mac/


1

Unlikely. SSD/usbs have firmware that automatically shuffles the available storage to account for errors in sections of the flash storage. Its possible that your important files are now stored on a bit of flash that effectively does not exist in the eyes of the OS and therefore can not be securely wiped. The easiest way to be fully sure that none of your ...


1

Firstly, my understanding is that an SSD that properly implements the secure erase command will erase the unallocated blocks, although it may be unable to erase retired/failed blocks (these are blocks that have worn out and no longer operate correctly) and in theory these could contain recoverable data. Secondly, HDDs also include reserved space. Most ...


1

Doing this is complete nonsense. All data on a modern iPhone (5s upward) is encrypted with a key which is derived from a key inside the CPU, another key stored in two copies in the flash memory, and usually the passcode is used as the third key. All you need to do is erase the two copies of the second of these three keys which is stored in the flash ...


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