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20

The reason you write '0' instead of '1' has to do with the way magnetic storage encodes the 0 and the 1. a long explanation of it can be found on Wikipedia under Run-length_limited. In short RLL is the methodology used to store the '1' and '0' and it is more complex than just to store the bit values themselves. On a side note to make the drive more like it ...


10

There are any number of different ways it can be done. In large part, the easiest way is following the link pointers to each of the chunks, but that isn't the only way by any means. (The MFT isn't the only source of those links in many file systems as well.) At a lower level, it can identify all the chunks and try to match some of them up on content if the ...


10

This is enough, or not, depending on the disk technology, the budget of the attacker, and some other details. When you fill a disk with zeros, you force the filesystem to reuse free blocks, and rewrite them. So, as first order approximation, this looks good for you: your file contents are overwritten. However, there are details: On some operating systems ...


9

Unlikely. It's AES-CBC-128, so there's no chance of you cracking the key. There are a few tools (e.g. Volatility, or Elcomsoft's forensics suite) that can recover the master key from a system memory dump, but that only works if the drive is already mounted and unlocked.


9

There are a few ways to solve this situation. One is to have the camera always encrypt one of the session keys to a camera backup key. The camera backup key is generated on account setup of the camera and a password is generated that is used to encrypt the backup key. This password is never stored on the camera itself. Your online storage would store the ...


7

What you describe is the worst possible practice possible apart from just handing it over. From a security standpoint it poses significant risks to both the previous and current parties. The easiest way to reformat PCs is to use what is called a "golden image" this image is a windows image you: keep up to date only install the bare minimum of programs ...


7

The best citation I can give is from Overwriting Hard Drive Data: The Great Wiping Controversy, which was published as part of the 4th International Conference on Information Systems Security, ICISS 2008. You can view the full text of the paper by viewing the book on Google Books, and jumping to page 243. The following excerpt is from their conclusion: ...


7

It is not possible to create a digital communication that will self-destruct after a certain amount of time (or upon sender's command). This because of the nature of the message, which once reaches the recipient' machine can be copied at will. This applies to email as well as instant messages. Therefore any service promising you messages that ...


6

If you use sdelete from Microsoft (http://technet.microsoft.com/en-us/sysinternals/bb897443.aspx) you don't have to install anything. It has an option to fill the unused disk space with zeroes too. If you already deleted the files this is what I'd just to make sure that nothing remains of the original file.


6

How does the Recycle Bin work? When you delete a file from a hard drive the file is moved to a folder named $Recycle.Bin on the same drive. So when you delete the file D:\Work_Files\SuperWeirdPr0n.mp4 it's actually moved to D:\$Recycle.Bin. How does that apply to TrueCrypt volumes? Well, pretty much the same. When you send a file from a mounted encrypted ...


6

The best cryptographers use cryptography only when necessary. That being said, this proposed design is needlessly complex. Your design incorporates two different hash functions, symmetric and asymmetric encryption. Further more you make no mention of what attacks you are trying prevent, which leads to a superstitious design that is difficult to ...


5

The virtual machine usually stores its virtual hard disk as a normal file on the host operating system's filesystem. Think of a filesystem like a warehouse. The warehouse contains a large number of boxes (files) and a manifest that lists all of the boxes (the file table). When you delete a file, it doesn't actually destroy the data, it just deletes the ...


5

First check with your legal expert if there are any laws in your country which require you to have a minimum retention period. For instance depending on your industry you might have to take into account either of these regulations: Sarbanes-Oxley regulations: To comply with SOX guidelines, companies must retain auditable emails for a minimum of five years ...


5

Due to the microscopic nature of current HDD internals this may no longer be possible... I once witnessed an 8" 12MB HDD having most of its data recovered after being "security wiped" with several passes of 0's, then 1's bit patterns. This may have been pre-RLL or RLE. I do not remember if the method employed had a name, which makes it difficult for me to ...


4

Many TPMs will allow a backup to be stored of the key either prior to loading it on to the TPM or via some kind of export. As long as you have the key, you can reload it on a new TPM if the TPM fries. I actually had this exact thing happen with an IBM ThinkPad with an early TPM where the TPM circuit fried and I had to replace the system board. I was ...


4

A forensic tool such as FTK imager, is essentially a binary data reader and interpreter. Oversimplified, it reads each value and shows you both the hexidecimal (or decimal) absolute value and/or the interpreted value (such as text). Google for more examples and explanations of how FTK imager works. Notice that a forensic toolkit is merely a tool. Most ...


4

Yes, it is a good strategy if a disk has held sensitive data and may be accessible by others. A Google search for "wipe disk free space" finds numerous such tools. There are a couple of other considerations. One is "slack space." That's the unused space in the last cluster of a file. It's not part of free space, so it won't get wiped by many disk wiping ...


3

A first method is to open up the old hard disk, and extract the platters. Hard drives are usually closed with screws, so it can be unscrewed; beware, though, that it is customary for hard disk vendors to hide the screws under stickers (a disk is sealed and letting the air in can kill it, so vendors want to prevent inquisitive customers from unknowingly ...


3

It depends. If you want to delete every trace of the file, it is more complex than overwriting sectors. Depending on which file system you are using, but if e.g. NTFS: even if you fill all free space, there can be things left behind in the MFT, journaling areas, etc. If it is a very small file, the entire file can be contained in the MFT, etc Also, ...


3

When you are using a HDD; writing filling it all up over and over again and changing file format and operating system and than filling it up over and over would help you. It is actually said that changing the OS and changing the file format (NFST to FAT32 etc) makes revocery pretty hard. And if you fill it up with newer data and do these practices in a ...


3

This question has been asked before, see here. The quick answer is that you're better off using a data shredding tool rather than trying to use encryption.


3

If you want to destroy all data on your disk, why not use a file shredding tool? There are plenty of them available, and it is a lot easier solution that creating a truecrypt volume and then deleting that volume. I also don't know how truecrypt initializes volumes. It is possible that truecrypt writes random data to the volume only once, while file ...


3

In NTFS, all of the metadata is stored in the MFT. This includes names, dates, parent folder, etc. the occupied clusters are also stored in there in a structure called data runs. The clusters storing the file data hold only file data and there is no linked list that holds info about the next or previous cluster. When a file is deleted (assuming a skip of ...


3

The aluminium coating of the CD reacts and creates plasma. So it burns the CD effectively. Below you can see the image of a microwaved CD. It's safe to say it's been destroyed.


3

You can't. If the private key is lost, then, essentially, you can only decrypt the data by recreating the key... organizations like the "TLA's" (FBI, CIA, NSA, etc.) are actively trying to do what you suggest. It is a hard problem, and that's why encryption works. In your case, the better option would be to create a new public/private key, and to then ...


2

As usual, the Wikipedia page contains useful links (Wikipedia is not "The Truth" but it is a great starting point for investigating technical issues and making one's own mind). In particular, it says that: As of November 2007, the United States Department of Defense considers overwriting acceptable for clearing magnetic media within the same security ...


2

If settings are default (ie, not using reversible encryption for password storage), then the user would have to log in to decrypt. In fact, if the user was ever to have their password administratively changed, then the files would become unrecoverable as the key would be lost.


2

If the file is ASCII armored, you may find the header at the top. -----BEGIN PGP MESSAGE----- Version: GnuPG v1.4.11 (GNU/Linux) jA0EAwMCSPY2a+zUrBBgySD3+GWiPhdcQbtKogerjG/50O9Q6f3FY78qqyxLBw00 RA== =DBXE -----END PGP MESSAGE----- If it isn't then you can try to review the specification, but it's complicated and after several minutes of reading I don't ...


2

TrueCrypt encrypts the whole volume, as a big bag of sectors. TrueCrypt does not know what a "file" is, it sees only sectors. It protects your data against people who steal your disk but do not know the password. The operating system manages the sectors, using some of them as metadata to describe directories and usage of other sectors for containing pieces ...



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