Difference between pages "Metadata" and "BitLocker Disk Encryption"

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'''Metadata''' is data about data. Metadata plays a number of important roles in [[computer forensics]]:
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'''BitLocker Disk Encryption''' (BDE) is [[Full Volume Encryption]] solution by [[Microsoft]] first included with the Enterprise and Ultimate editions of [[Windows|Windows Vista]]. It is also present in [[Windows|Windows 7]] along with a system for encrypting removable storage media devices, like [[USB]], which is called BitLocker To Go. Unlike previous versions of BitLocker, BitLocker To Go allows the user to protect volumes with a password or smart card.
* It can provide corroborating information about the document data itself.
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* It can reveal information that someone tried to hide, delete, or obscure.
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* It can be used to automatically correlate documents from different sources.
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Since metadata is fundamentally data, it suffers all of the data quality and pedigre issues as any other form of data. Nevertheless, because metadata isn't generally visible unless you use a special tool, more skill is required to alter or otherwise manipulate it.
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== BitLocker ==
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Volumes encrypted with BitLocker will have a different signature than the standard [[NTFS]] header. Instead, they have in their volume header (first sector): <tt>2D 46 56 45 2D 46 53 2D</tt> or, in ASCII, <tt>-FVE-FS-</tt>.
  
==Kinds of Metadata==
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These volumes can be identified by the BitLocker GUID/UUID: 4967d63b-2e29-4ad8-8399-f6a339e3d00.
Some kinds of metadata that are interesting in computer forensics:
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* [[File system]] metadata (e.g. [[MAC times]], [[access control lists]], etc.)
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* Digital image metadata. Although information such as the image size and number of colors are technically metadata, [[JPEG]] and other file formats store additional data about the photo or the device that acquired it.
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* Document metadata, such as the creator of a document, it's last print time, etc.
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==File types that support metadata and extraction tools==
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The actual data on the encrypted volume is protected with either 128-bit or 256-bit [[AES]] and optionally diffused using an algorithm called Elephant. The key used to do the encryption, the Full Volume Encryption Key (FVEK) and/or TWEAK key, is stored in the BitLocker metadata on the protected volume. The FVEK and/or TWEAK keys are encrypted using another key, namely the Volume Master Key (VMK). Several copies of the VMK are also stored in the metadata. Each copy of the VMK is encrypted using another key, also know as key-protector key. Some of the key-protectors are:
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* TPM (Trusted Platform Module)
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* Smart card
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* recovery password
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* start-up key
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* clear key; this key-protector provides no protection
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* user password
  
Below are some common data and metadata formats, the files in which they are found, and a collection of tools that can be used to extract information.
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BitLocker has support for partial encrypted volumes.
  
; [[EXIF]] ([[JPEG]] and [[TIFF]] image files; Music Files)
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== BitLocker To Go ==
: The [[Exchangeable Image File]] format describes a format for a block of data that can be embedded into JPEG and TIFF image files, as well as [[RIFF WAVE]] audio files. Information includes date and time information, camera settings, location information, textual descriptions, and copyright information.
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Volumes encrypted with BitLocker To Go will have a hybrid encrypted volume, meaning that part of the volume is unencrypted and contains applications to unlock the volume and the other part of the volume is encrypted. The "discovery drive" volume contains BitLocker To Go Reader to read from encrypted volumes on versions of Microsoft [[Windows]] without BitLocker support.
:* [http://pel.sourceforge.net/ PEL: PHP Exif Library]
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:* [http://libexif.sourceforge.net/ LibExif] (C)
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:* [http://www.drewnoakes.com/code/exif/ Metadata extraction in Java]
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; [[ID3]] ([[MP3]] files)
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== manage-bde ==
: Implemented as a small block of data stored at the end of MP3 files. [[ID3v1]] is a 128-byte block in a specified format allowing 30 bytes for song, artist and album, 4 bytes for year, 30 bytes for comment, and 1 byte for genre. [[ID3v1.1]] adds a track number. [[ID3v2]] is a general container structure. For more information, see [http://www.id3.org/].
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To view the BitLocker Drive Encryption (BDE) status on a running Windows system:
:* [http://id3lib.sourceforge.net/ id3lib], a widely-used open source C/C++ ID3 implementation.
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<pre>
:* [http://www.vdheide.de/projects.html Java library MP3]
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manage-bde.exe -status
:* [http://search.cpan.org/dist/MP3-Info/ MP3::Info] (Perl)
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</pre>
:* [http://search.cpan.org/dist/MPEG-ID3v2Tag/ MPEG::ID3v2Tag] (Perl)
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; [[Microsoft]] [[OLE 2]]
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To obtain the recovery password for volume C:
: Microsoft Office document files contain a huge amount of metadata. They are created as OLE 2 files. Here are some tools for processing them:  
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<pre>
:* [http://jakarta.apache.org/poi/index.html Jakarta POI] Open Source implementation in Java.
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manage-bde.exe -protectors -get C: -Type recoverypassword
:* [http://www.payneconsulting.com/ Payne Consulting] Metadata Analysis and cleanup.
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</pre>
:* [http://www.inforenz.com/software/forager.html Inforenz Forager] Inforenz Forager
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; [[TIFF]]
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Or just obtain the all “protectors” for volume C:
: The [[Tagged Image File Format]] allows one or more images to be bundled in a single file. Multiple [[compression]] formats are supported. [[EXIF]] files can be stored inside TIFFs.
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<pre>
:* [http://www.remotesensing.org/libtiff/ LibTIFF]
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manage-bde.exe -protectors -get C:
:* [http://www.awaresystems.be/imaging/tiff/faq.html TIFF FAQ]
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</pre>
  
=External links=
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== See Also ==
* [http://en.wikipedia.org/wiki/Metadata Wikipedia: Metadata]
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* [[BitLocker:_how_to_image]]
* [http://theses.nps.navy.mil/08Jun_Migletz.pdf Automated Metadata Extraction], Maj. James Migletz, Master's Thesis, Naval Postgraduate School, June 2008
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* [[Defeating Whole Disk Encryption]]
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== External Links ==
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* [http://www.nvlabs.in/archives/1-NVbit-Accessing-Bitlocker-volumes-from-linux.html NVbit : Accessing Bitlocker volumes from linux], 2008
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* Jesse D. Kornblum, [http://jessekornblum.com/publications/di09.html Implementing BitLocker for Forensic Analysis], ''Digital Investigation'', 2009
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* [http://en.wikipedia.org/wiki/BitLocker_Drive_Encryption Wikipedia entry on BitLocker]
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* [http://technet2.microsoft.com/WindowsVista/en/library/c61f2a12-8ae6-4957-b031-97b4d762cf311033.mspx?mfr=true Microsoft's Step by Step Guide]
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* [http://technet.microsoft.com/en-us/windowsvista/aa906017.aspx Microsoft Technical Overview]
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* [http://technet.microsoft.com/en-us/magazine/2009.05.win7.aspx An Introduction to Security in Windows 7]
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* [http://www.microsoft.com/whdc/system/platform/hwsecurity/BitLockerFAQ.mspx Microsoft FAQ]
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* [http://www.microsoft.com/downloads/details.aspx?FamilyID=131dae03-39ae-48be-a8d6-8b0034c92555&DisplayLang=en Microsoft Description of the Encryption Algorithm]
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* [http://secude.com/htm/801/en/White_Paper%3A_Cold_Boot_Attacks.htm Cold Boot Attacks, Full Disk Encryption, and BitLocker]
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* [http://technet.microsoft.com/en-us/library/hh831412.aspx What's New in BitLocker] in Windows 8
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== Tools ==
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* [http://www.hsc.fr/ressources/outils/dislocker/ dislocker]
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* [[libbde]]
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[[Category:Disk encryption]]
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[[Category:Windows]]

Revision as of 02:00, 27 June 2013

BitLocker Disk Encryption (BDE) is Full Volume Encryption solution by Microsoft first included with the Enterprise and Ultimate editions of Windows Vista. It is also present in Windows 7 along with a system for encrypting removable storage media devices, like USB, which is called BitLocker To Go. Unlike previous versions of BitLocker, BitLocker To Go allows the user to protect volumes with a password or smart card.

BitLocker

Volumes encrypted with BitLocker will have a different signature than the standard NTFS header. Instead, they have in their volume header (first sector): 2D 46 56 45 2D 46 53 2D or, in ASCII, -FVE-FS-.

These volumes can be identified by the BitLocker GUID/UUID: 4967d63b-2e29-4ad8-8399-f6a339e3d00.

The actual data on the encrypted volume is protected with either 128-bit or 256-bit AES and optionally diffused using an algorithm called Elephant. The key used to do the encryption, the Full Volume Encryption Key (FVEK) and/or TWEAK key, is stored in the BitLocker metadata on the protected volume. The FVEK and/or TWEAK keys are encrypted using another key, namely the Volume Master Key (VMK). Several copies of the VMK are also stored in the metadata. Each copy of the VMK is encrypted using another key, also know as key-protector key. Some of the key-protectors are:

  • TPM (Trusted Platform Module)
  • Smart card
  • recovery password
  • start-up key
  • clear key; this key-protector provides no protection
  • user password

BitLocker has support for partial encrypted volumes.

BitLocker To Go

Volumes encrypted with BitLocker To Go will have a hybrid encrypted volume, meaning that part of the volume is unencrypted and contains applications to unlock the volume and the other part of the volume is encrypted. The "discovery drive" volume contains BitLocker To Go Reader to read from encrypted volumes on versions of Microsoft Windows without BitLocker support.

manage-bde

To view the BitLocker Drive Encryption (BDE) status on a running Windows system:

manage-bde.exe -status

To obtain the recovery password for volume C:

manage-bde.exe -protectors -get C: -Type recoverypassword

Or just obtain the all “protectors” for volume C:

manage-bde.exe -protectors -get C:

See Also

External Links

Tools