Difference between pages "CPR Tools" and "Encase image file format"

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CPR Tools is a LaBelle, FL, US company that makes a variety of hardware and software products for computer forensics specializing, data recovery and data security:
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The Encase image file format is used by [[EnCase]] used to store various types of digital evidence e.g.
 +
* 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
  
  
== PSIClone ==
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The format is (reportedly) based on ASR Data's Expert Witness Compression Format [http://www.asrdata.com/SMART/whitepaper.html].
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Currently there are 2 version of the format; version 1 is a closed format and was succeeded by version 2 in EnCase 7, for which a format specification is available, but requires registration.
  
:The company's flagship data recovery product.
 
  
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The media data can be stored in multiple evidence files, which are called segment files.
== Hammer ==
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Each segment file consist of multiple sections, which has a distinct section start definition containing a section type.
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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.
  
: Performs NIST 800-88 compliant data erasure on up to four (4) devices at a time, using the ATA Secure Erase command as a primary mechanism (if available), and using embedded version of the company's BangDisk for drives do not support ATA Secure Erase.
 
  
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EnCase allows to store the data compressed either using a fast or best level of the deflate compression method.
== SCSIHammer ==
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EnCase 7 no longer distinguishes between fast or best compression and just provides for either uncompressed or compressed.
  
: Performs NIST 800-88 compliant data erasure on up to thirty (30) drives at a time when attached to external arrays/shelves/controllers.  Data eradication is simultaneous on all drives and works at the highest native speed for each drive.
 
  
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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.
  
== AlarmDisk ==
 
 
: A personal computer security monitoring system (freeware).  Allows users to tell if their drive has been powered without their knowledge. This product represents a significant breakthrough in personal computing security and intrusion detection.  Download.com rated this free product 4 of 5 editor's stars.  Tucows rated this product 5 stars out of 5.
 
  
The company also offers training throughout the calendar year.  
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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.
  
== External Links ==
 
* [http://www.cprtools.net Official website]
 
* [http://www.cprtools.net/store Official Online Shopping Portal]
 
  
[[Category:Vendor]]
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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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 +
 
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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
 +
* 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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[[EnCase]]
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== External Links ==
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* [http://web.archive.org/web/20100905235827/http://www.asrdata.com/SMART/whitepaper.html Internet archive copy of: ASR Data's Expert Witness Compression Format]
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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]]

Revision as of 03:26, 15 July 2012

The Encase image file format is used by EnCase used to store various types of digital evidence e.g.

  • disk image (physical bitstream of an acquired disk)
  • volume image
  • memory
  • logical files


The format is (reportedly) based on ASR Data's Expert Witness Compression Format [1]. Currently there are 2 version of the format; version 1 is a closed format and was succeeded by version 2 in EnCase 7, for which a format specification is available, but requires registration.


The media data can be stored in multiple evidence files, which are called segment files. Each segment file consist of multiple sections, which has a distinct section start definition containing a section type. 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.


EnCase allows to store the data compressed either using a fast or best level of the deflate compression method. EnCase 7 no longer distinguishes between fast or best compression and just provides for either uncompressed or compressed.


Besides digital evidence the evidence files, or segment files, contain a header containing case information. The case information which entails date and time of acquisition, an examiner's name, notes on the acquisition, and an optional password.

  • 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.
  • As of EnCase 4 an additional "header2" section was added. The "header" section now appears only once, but the new "header2" section twice.


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). As of EnCase 5 the number of sectors per block (chunk) can vary. 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. 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. As of EnCase 5 the granularity of unreadable chunks can vary.


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. As of EnCase 6 the option to store a SHA1 hash was added.


EnCase 5 and later have the option to store single files into the EnCase Logical Evidence File (LEF) or EWF-L01. This format changed slightly in EnCase 6 and 7.


In EnCase 7 the EWF format was succeeded by the EnCase Evidence File Format Version 2 (EWF2-EX01 and EWF2-LX01). EWF2-EX01 is at it's lower levels a different format then EWF-E01 and provides support for:

  • bzip2 compression
  • direct encryption (AES-256) of the section data

The same features are added to the new logical evidence file format (EWF2-LX01) with the exception of encryption. EWF2-EX01, EWF2-LX01 are not backwards compatible with previous EnCase products.

See Also

EnCase

External Links