Difference between pages "Books" and "Disk Imaging"

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=General books about forensics=
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|- style="background:#bfbfbf; font-weight: bold"
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! width="30%"|Title
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! width="20%"|Author
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! width="10%"|ISBN
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! width="20%"|Publisher
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! width="10%"|Publication Date
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! width="10%"|Comment
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|-
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|[http://www.amazon.com/gp/product/0849381274/ Principles and Practice of Criminalistics: The Profession of Forensic Science]
+
|Keith Inman and Norah Rudin
+
|0849381274
+
|CRC Press
+
|Aug 29, 2000
+
|Highly Recommended
+
|-
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|[http://www.amazon.com/gp/product/0130910589/ Forensic Science Handbook, Volume I (2nd Edition)]
+
|Richard E. Saferstein, Ed.
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|0130910589
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|Prentice Hall
+
|Jun 5, 2001
+
|-
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|[http://www.amazon.com/gp/product/013112434X/ Forensic Science Handbook, Volume II (2nd Edition)]
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|Richard E. Saferstein, Ed.
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|013112434X
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|Prentice Hall
+
|Oct 8, 2004
+
|-
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|[http://www.amazon.com/gp/product/0133253902/ Forensic Science Handbook, Volume III]
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|Richard E. Saferstein, Ed.
+
|0133253902
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|Prentice Hall
+
|Apr 22, 1993
+
|-
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|[http://www.crcpress.com/shopping_cart/products/product_detail.asp?sku=2747&parent_id=411&pc= Forensic Science: An Introduction to Scientific and Investigative Techniques, Second Edition]
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|Stuart James and Jon J Nordby
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|0849327474
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|CRC Press
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|Feb 10, 2005
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|-
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|[http://www.crcpress.com/shopping_cart/products/product_detail.asp?sku=0860&parent_id=411&pc= Ethics in Forensic Science: Professional Standards for the Practice of Criminalistics]
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|Peter D Barnett
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|0849308607
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|CRC Press
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|Jun 27, 2001
+
|-
+
|}
+
  
=Books about computer forensics=
+
Disk imaging is the process of making a bit-by-bit copy of a disk. Imaging (in more general terms) can apply to anything that can be considered as a bit-stream, e.g. a physical or logical volumes, network streams, etc.
{| border="0" cellpadding="2" cellspacing="2" align="top"
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|- style="background:#bfbfbf; font-weight: bold"
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! width="30%"|Title
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! width="20%"|Author
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! width="10%"|ISBN
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! width="20%"|Publisher
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! width="10%"|Publication Date
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! width="10%"|Comment
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|-
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|[http://www.awprofessional.com/title/0321268172 File System Forensic Analysis]
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|[[Brian Carrier]]
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|321268172
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|Addision-Wesley
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|27-Mar-05
+
|(Highly recommended)
+
|-
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[http://www.crcpress.com/shopping_cart/products/product_detail.asp?sku=8158&parent_id=411&pc= Investigating Computer Crime]
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|Franklin Clark and Ken Diliberto
+
|849381584
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|CRC Press
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|11-Jul-96
+
|
+
|-
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[http://www.crcpress.com/shopping_cart/products/product_detail.asp?sku=2218&parent_id=411&pc= Investigating Computer-Related Crime]
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|Peter Stephenson
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|849322189
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|CRC Press
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|28-Sep-99
+
|
+
|-
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[http://www.ncjrs.gov/pdffiles1/nij/187736.pdf Electronic Crime Scene Investigation: A Guide for First Responders]
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|NCJ 187736
+
|
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|National Institute of Justice
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|Jul-01
+
|NIJ Guide
+
|
+
|-
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[http://www.crcpress.com/shopping_cart/products/product_detail.asp?sku=AU0955&parent_id=411&pc= Cyber Forensics: A Field Manual for Collecting, Examining, and Preserving Evidence of Computer Crimes]
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|Albert J Marcella, Jr. and Robert S Greenfield
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|849309557
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|Auerbach Publications
+
|23-Jan-02
+
|
+
|-
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[http://books.mcgraw-hill.com/getbook.php?isbn=007222696X Incident Response & Computer Forensics, Second Edition]
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|Kevin Mandia, Chris Prosise & Matt Pepe
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|007222696X
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|McGraw-Hill/Osborne
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|17-Jul-03
+
|
+
|-
+
[http://www.crcpress.com/shopping_cart/products/product_detail.asp?id=&parent_id=411&sku=AU2433&pc= Investigator's Guide to Steganography]
+
|Gregory Kipper
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|849324335
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|Auerbach Publications
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|27-Oct-03
+
|
+
|-
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[http://www.amazon.com/gp/product/0121631044 Digital Evidence and Computer Crime] Second Edition
+
|Eoghan Casey
+
|121631044
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|Academic Press
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|22-Mar-04
+
|
+
|-
+
[http://www.ncjrs.gov/pdffiles1/nij/199408.pdf Forensic Examination of Digital Evidence: A Guide for Law Enforcement]
+
|NCJ 199408
+
|
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|National Institute of Justice
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|Apr-04
+
|Special Report
+
|-
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[http://www.awprofessional.com/bookstore/product.asp?isbn=0321200985&rl=1 Windows Forensics and Incident Recovery]
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|[[Harlan Carvey]]
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|321200985
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|Addison Wesley Professional
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|21-Jul-04
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|
+
|-
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[http://www.syngress.com/catalog/?pid=4220 CD and DVD Forensics]
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|[[Paul Crowley]] and [[Dave Kleiman]](Technical Editor)
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|1597491284
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|Syngress
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|8-Nov-06
+
|
+
|-
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[http://www.sybex.com/WileyCDA/SybexTitle/productCd-0470097620.html Mastering Windows Network Forensics and Investigation]
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|Steven Anson and Steve Bunting
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|9.78047E+12
+
|Sybex
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|Apr-07
+
|
+
|-
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[http://www.syngress.com/catalog/?pid=4230 Windows Forensic Analysis]
+
|[[Harlan Carvey]]
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|159749156X
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|Syngress (Elsevier)
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|21-May-07
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|
+
|-
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[http://www.amazon.com/gp/product/020163497X Forensic Discovery]
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|Dan Farmer and Wietse Venema
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|321703251
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|Addison-Wesley
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|28-Dec-09
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|[http://www.porcupine.org/forensics/forensic-discovery/ HTML version] of the book is freely available online.
+
|-
+
  
|}
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The most straight-forward disk imaging method is reading a disk from start to end and writing the data to a [[:Category:Forensics_File_Formats|Forensics image format]].
 +
This can be a time consuming process especially for disks with a large capacity.
  
=Books in other languages=
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The process of disk imaging is also referred to as disk duplication.
  
=== German ===
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== Disk Imaging Solutions ==
{| border="0" cellpadding="2" cellspacing="2" align="top"
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See: [[:Category:Disk Imaging|Disk Imaging Solutions]]
|- style="background:#bfbfbf; font-weight: bold"
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! width="30%"|Title
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! width="20%"|Author
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! width="10%"|ISBN
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! width="20%"|Publisher
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! width="10%"|Publication Date
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! width="10%"|Comment
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|-
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|[http://www.dpunkt.de/buecher/3-89864-379-4.html Computer-Forensik], 2nd edition
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|Alexander Geschonneck
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|3898643794
+
|
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|2006
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|[http://www.computer-forensik.org/ Errata] and blog of the author
+
|-
+
|}
+
  
=== Italian ===
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== Common practice ==
{| border="0" cellpadding="2" cellspacing="2" align="top"
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It common practice to use a [[Write Blockers|Write Blocker]] when imaging a pyhical disk. The write blocker is an additional measure to prevent write access to the disk.
|- style="background:#bfbfbf; font-weight: bold"
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! width="30%"|Title
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! width="20%"|Author
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! width="10%"|ISBN
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! width="20%"|Publisher
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! width="10%"|Publication Date
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! width="10%"|Comment
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|-
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|[http://www.apogeonline.com/libri/88-503-2593-2/scheda Computer Forensics] 1st edition
+
|Andrea Ghirardini and Gabriele Faggioli
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|8850325932
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|Apoge
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|May 17, 2007
+
|EAN 9788850325931
+
|-
+
|}
+
  
=== Portuguese ===
+
Also see: [[DCO and HPA|Device Configuration Overlay (DCO) and Host Protected Area (HPA)]]
{| border="0" cellpadding="2" cellspacing="2" align="top"
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|- style="background:#bfbfbf; font-weight: bold"
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! width="30%"|Title
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! width="20%"|Author
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! width="10%"|ISBN
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! width="20%"|Publisher
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! width="10%"|Publication Date
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! width="10%"|Comment
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|-
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|[http://www.brasport.com.br/index.php?Escolha=8&Livro=L00194 Perícia Forense Aplicada à Informática] 1st edition
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|Andrey Rodrigues de Freitas
+
|8574522260
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|Brasport
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|2006
+
|-
+
|}
+
  
=== Russian ===
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== Integrity ==
{| border="0" cellpadding="2" cellspacing="2" align="top"
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Often when creating a disk image a [http://en.wikipedia.org/wiki/Cryptographic_hash_function cryptographic hash] is calculated of the entire disk. Commonly used cryptographic hashes are MD5, SHA1 and/or SHA256.
|- style="background:#bfbfbf; font-weight: bold"
+
 
! width="30%"|Title
+
 
! width="20%"|Author
+
By recalculating the integrity hash at a later time, one can determine if the data in the disk image has been changed. This by itself provides no protection against intentional tampering, but can indicate that the data was altered, e.g. due to corruption. The integrity hash does not indicate where int he data the alteration has occurred. Therefore some image tools and/or formats provide for additional integrity checks like:
! width="10%"|ISBN
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* A checksum
! width="20%"|Publisher
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* Parity data
! width="10%"|Publication Date
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* [[Piecewise hashing]]
! width="10%"|Comment
+
 
|-
+
== Smart imaging ==
|[http://forensics.ru/ Форензика – компьютерная криминалистика]
+
Smart imaging is a combination of techniques to make the imaging process more intelligent.
|N. N. Fedotov
+
* Compressed storage
|
+
* Deduplication
|
+
* Selective imaging
|
+
* Decryption while imaging
|-
+
 
|}
+
=== Compressed storage ===
 +
 
 +
A common technique to reduce the size of an image file is to compress the data. Where the compression method should be [http://en.wikipedia.org/wiki/Lossless_data_compression lossless].
 +
On modern computers, with multiple cores, the compression can be done in parallel reducing the output without prolonging the imaging process.
 +
Since the write speed of the target disk can be a bottleneck in imaging process, parallel compression can reduce the total time of the imaging process.
 +
[[Guymager]] was one of the first imaging tools to implement the concept of multi-process compression for the [[Encase image file format]]. This technique is now used by various imaging tools including [http://www.tableau.com/index.php?pageid=products&model=TSW-TIM Tableau Imager (TIM)]
 +
 
 +
Other techniques like storing the data sparse, using '''empty-block compression''' or '''pattern fill''', can reduce the total time of the imaging process and the resulting size of new non-encrypted (0-byte filled) disks.
 +
 
 +
=== Deduplication ===
 +
Deduplication is the process of determining and storing data that occurs more than once on-disk, only once in the image.
 +
It is even possible to store the data once for a corpus of images using techniques like hash based imaging.
 +
 
 +
=== Selective imaging ===
 +
Selective imaging is a technique to only make a copy of certain information on a disk like the $MFT on an [[NTFS]] volume with the necessary contextual information.
 +
 
 +
[[EnCase]] Logical Evidence Format (LEF) is an example of a selective image; although only file related contextual information is stored in the format by [[EnCase]].
 +
 
 +
=== Decryption while imaging ===
 +
Encrypted data is worst-case scenario for compression. Because the encryption process should be deterministic, a solution to reduce the size of an encrypted image is to store it non-encrypted and compressed and encrypt it again on-the-fly if required. Although this should be rare since the non-encrypted data is what undergoes analysis.
 +
 
 +
== Also see ==
 +
* [[:Category:Forensics_File_Formats|Forensics File Formats]]
 +
* [[Write Blockers]]
 +
* [[Piecewise hashing]]
 +
* [[Memory Imaging]]
 +
 
 +
== External Links ==
 +
* [http://www.tableau.com/pdf/en/Tableau_Forensic_Disk_Perf.pdf Benchmarking Hard Disk Duplication Performance in Forensic Applications], by [[Robert Botchek]]
 +
 
 +
=== Hash based imaging ===
 +
* [http://www.dfrws.org/2010/proceedings/2010-314.pdf Hash based disk imaging using AFF4], by [[Michael Cohen]], [[Bradley Schatz]]
 +
 
 +
[[Category:Disk Imaging]]

Revision as of 04:29, 28 July 2012

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Please help to improve this article by expanding it.
Further information might be found on the discussion page.

Disk imaging is the process of making a bit-by-bit copy of a disk. Imaging (in more general terms) can apply to anything that can be considered as a bit-stream, e.g. a physical or logical volumes, network streams, etc.

The most straight-forward disk imaging method is reading a disk from start to end and writing the data to a Forensics image format. This can be a time consuming process especially for disks with a large capacity.

The process of disk imaging is also referred to as disk duplication.

Contents

Disk Imaging Solutions

See: Disk Imaging Solutions

Common practice

It common practice to use a Write Blocker when imaging a pyhical disk. The write blocker is an additional measure to prevent write access to the disk.

Also see: Device Configuration Overlay (DCO) and Host Protected Area (HPA)

Integrity

Often when creating a disk image a cryptographic hash is calculated of the entire disk. Commonly used cryptographic hashes are MD5, SHA1 and/or SHA256.


By recalculating the integrity hash at a later time, one can determine if the data in the disk image has been changed. This by itself provides no protection against intentional tampering, but can indicate that the data was altered, e.g. due to corruption. The integrity hash does not indicate where int he data the alteration has occurred. Therefore some image tools and/or formats provide for additional integrity checks like:

Smart imaging

Smart imaging is a combination of techniques to make the imaging process more intelligent.

  • Compressed storage
  • Deduplication
  • Selective imaging
  • Decryption while imaging

Compressed storage

A common technique to reduce the size of an image file is to compress the data. Where the compression method should be lossless. On modern computers, with multiple cores, the compression can be done in parallel reducing the output without prolonging the imaging process. Since the write speed of the target disk can be a bottleneck in imaging process, parallel compression can reduce the total time of the imaging process. Guymager was one of the first imaging tools to implement the concept of multi-process compression for the Encase image file format. This technique is now used by various imaging tools including Tableau Imager (TIM)

Other techniques like storing the data sparse, using empty-block compression or pattern fill, can reduce the total time of the imaging process and the resulting size of new non-encrypted (0-byte filled) disks.

Deduplication

Deduplication is the process of determining and storing data that occurs more than once on-disk, only once in the image. It is even possible to store the data once for a corpus of images using techniques like hash based imaging.

Selective imaging

Selective imaging is a technique to only make a copy of certain information on a disk like the $MFT on an NTFS volume with the necessary contextual information.

EnCase Logical Evidence Format (LEF) is an example of a selective image; although only file related contextual information is stored in the format by EnCase.

Decryption while imaging

Encrypted data is worst-case scenario for compression. Because the encryption process should be deterministic, a solution to reduce the size of an encrypted image is to store it non-encrypted and compressed and encrypt it again on-the-fly if required. Although this should be rare since the non-encrypted data is what undergoes analysis.

Also see

External Links

Hash based imaging