Difference between pages "Encase image file format" and "Cellebrite UFED"

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(New page: The Cellebrite 'Universal Forensic Extraction Device' , or UFED, is a unique and very cost effective mobile phone forensic device that is completely stand alone. As of September 2008, th...)
 
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The Encase image file format is used by [[EnCase]] used to store various types of digital evidence e.g.
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The Cellebrite 'Universal Forensic Extraction Device' , or UFED, is a unique and very cost effective mobile phone forensic device that is completely stand alone.  
* disk image (physical bitstream of an acquired disk)
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* volume image
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* memory
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* logical files
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As of September 2008, the UFED is compatible with 1,625 mobile phones (including GSM, TDMS, CDMA), with the standard package containing 66 different phone cables. Wireless connection options are also integrated into the UFED, such as IR and Bluetooth. 
  
Currently there are 2 versions of the format:
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Using the MD5 Hash Algorithm, retrieved data includes:
* version 1 is (reportedly) based on [[:File:ASR Data's Expert Witness Compression Format.pdf|ASR Data's Expert Witness Compression Format]].
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* version 2 was introduced in EnCase 7, for which a format specification (at least for Ex01) is available, but requires registration.
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– Phonebook
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– SMS and MMS messages
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- SIM data
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- Multimedia (images, videos, audio, ect.)
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- Date and Time stamps
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- Deleted data
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- and much more.  
  
The libewf project indicates that the January 2012 version of the version 2 format specification, besides Lx01 not being specified, is sufficient to read the format but not complete.
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The UFED is flexible enough to be used in many environments, such as:
  
== Version 1 ==
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- Fixed to a desk in a crime lab connect to a PC
The media data can be stored in multiple evidence files, which are called segment files.
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- Fixed to a desk in a crime lab (stand alone with no PC)
Each segment file consist of multiple sections, which has a distinct section start definition containing a section type.
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- Mobile in a car or at a VCP (connected to car 12V power)
Up to EnCase 5 the segment file were limited to 2 GiB, due to the internal 31-bit file offset representation. This limitation was lifted by adding a base offset value in EnCase 6.
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- Mobile in the field (using battery kit)
  
 
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While the UFED is completely stand alone, additional software is included to create specialised reports on the retrieved raw data. Customised reports give the additional option of containing your own logo, case file number, address, etc.
EnCase allows to store the data compressed either using a fast or best level of the deflate compression method.
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EnCase 7 no longer distinguishes between fast or best compression and just provides for either uncompressed or compressed.
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Besides digital evidence the evidence files, or segment files, contain a header containing case information.
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The case information which entails date and time of acquisition, an examiner's name, notes on the acquisition, and an optional password.
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* In EnCase 3 the case information header is stored in the "header" section, which is defined twice within the file and contain the same information.
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* As of EnCase 4 an additional "header2" section was added. The "header" section now appears only once, but the new "header2" section twice.
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The format adds error detection by storing the data with checksums (Adler32), for both the metadata as the data blocks, which are by default 64 x 512 byte sectors (32 KiB).
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As of EnCase 5 the number of sectors per block (chunk) can vary.
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EnCase 3F introduced an "error2" section that it uses to record the location and number of bad sector chunks. The way it handles the sections it can't read is that those areas are filled with zero.
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Then EnCase displays to the user the areas that could not be read when the image was acquired. The granularity of unreadable chunks appears to be 32K.
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As of EnCase 5 the granularity of unreadable chunks can vary.
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EnCase 3 can store a one-way hash of the data. For a bitstream it does so by calculating e.g. a MD5 hash of the original media data and adds a hash section to the last of the segment file.
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As of EnCase 6 the option to store a SHA1 hash was added.
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EnCase 5 and later have the option to store '''single files''' into the EnCase Logical Evidence File (LEF) or EWF-L01.
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This format changed slightly in EnCase 6 and 7.
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== Version 2 ==
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In EnCase 7 the EWF format was succeeded by the EnCase Evidence File Format Version 2 (EWF2-EX01 and EWF2-LX01).
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EWF2-EX01 is at it's lower levels a different format then EWF-E01 and provides support for:
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* bzip2 compression
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* direct encryption (AES-256) of the section data
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The same features are added to the new logical evidence file format (EWF2-LX01) with the exception of encryption.
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EWF2-EX01, EWF2-LX01 are not backwards compatible with previous EnCase products.
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== See Also ==
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* [[:File:ASR Data's Expert Witness Compression Format.pdf|ASR Data's Expert Witness Compression Format]]
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* [[EnCase]]
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== External Links ==
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* [http://www.guidancesoftware.com/DocumentRegistration.aspx?did=1000018246 EnCase Evidence File Format Version 2], requires registration
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* [http://code.google.com/p/libewf/downloads/detail?name=Expert%20Witness%20Compression%20Format%20%28EWF%29.pdf Expert Witness Compression Format (EWF)].
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* [http://code.google.com/p/libewf/downloads/detail?name=Expert%20Witness%20Compression%20Format%202%20%28EWF2%29.pdf Expert Witness Compression Format (EWF) version 2].
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* [http://www.cfreds.nist.gov/v2/Basic_Mac_Image.html Sample image in EnCase, iLook, and dd format] - From the [[Computer Forensic Reference Data Sets]] Project
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[[Category:Forensics File Formats]]
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Revision as of 20:01, 16 September 2008

The Cellebrite 'Universal Forensic Extraction Device' , or UFED, is a unique and very cost effective mobile phone forensic device that is completely stand alone.

As of September 2008, the UFED is compatible with 1,625 mobile phones (including GSM, TDMS, CDMA), with the standard package containing 66 different phone cables. Wireless connection options are also integrated into the UFED, such as IR and Bluetooth.

Using the MD5 Hash Algorithm, retrieved data includes:

– Phonebook – SMS and MMS messages - SIM data - Multimedia (images, videos, audio, ect.) - Date and Time stamps - Deleted data - and much more.

The UFED is flexible enough to be used in many environments, such as:

- Fixed to a desk in a crime lab connect to a PC - Fixed to a desk in a crime lab (stand alone with no PC) - Mobile in a car or at a VCP (connected to car 12V power) - Mobile in the field (using battery kit)

While the UFED is completely stand alone, additional software is included to create specialised reports on the retrieved raw data. Customised reports give the additional option of containing your own logo, case file number, address, etc.