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Digital forensic workflows

Owned by Creighton Barrett
Last updated: Sept 07, 2018
3 min read

Introduction

  • This page describes basic digital forensics workflows. 

Data acquisition workflows

There are three basic workflows for acquiring data:

WorkflowDescriptionRationale
Workflow #1 – Forensic imaging for digital preservation backlog
  1. Add item to register of digital storage devices.
  2. Create image.
  3. Transfer forensic image to digital backlog until further processing is scheduled.
  4. Delete image from local storage after transfer is validated.
Select this workflow in cases where processing is unscheduled. A secondary copy is not necessary if processing is unscheduled. The primary image can be transferred to digital backlog and a copy can be transferred back to the Forensics Lab when processing is scheduled.

Workflow #2 – Forensic processing (small cases)

Create two copies of forensic image and keep both copies on forensic tower while processing one version of the image

  1. Add items to register of digital storage devices.
  2. Create image.
  3. Ingest images into FTK.
  4. Select files from forensic images.
  5. Export selected files.
  6. Package files and ingest into digital preservation system.
Select this workflow in cases where forensic processing is scheduled and total storage requirements for primary forensic images does not exceed 1 TB​. A secondary copy is necessary anytime forensic processing takes place but, with cases that involve less than 500 GB of data, the secondary copy can usually be stored on local RAID storage until processing is complete. This protects the primary copy and reduces unnecessary data transfer.

Workflow #3 – Forensic processing (large cases)


Create two copies of forensic image, transfer copy to digital backlog before processing​ primary image

Select this workflow in cases where forensic processing is scheduled and the total storage requirements for primary and secondary copies of forensic images exceeds 1 TB. 

A secondary copy is necessary anytime forensic processing takes place but, with cases that involve more than 500 GB of data, the secondary copy will occupy too much space on local RAID storage.

Forensic imaging for digital preservation backlog

  1. Add item to register of digital storage devices.

  2. Prepare item for forensic imaging.

  3. Use FTK Imager to create forensic image of item.

  4. Transfer forensic image to Libraries' digital backlog storage until further processing.

  5. Delete local copy of forensic image after transfer validation.

  6. Update entry in register of digital storage devices.

Forensic processing (small cases)

  1. Add item to register of digital storage devices.

  2. Prepare item for forensic imaging.

  3. Use FTK Imager to create forensic image of item and create a secondary (i.e., local backup) copy of the forensic image.

  4. Update entry in register of digital storage devices.

  5. Create case in FTK.

  6. Select an evidence processing profile.
  7. Add forensic image to case.

  8. Run additional analysis processing. Use a combination of tools to identify confidential and personal information.

  9. Create filters as necessary.

  10. Create labels to support archival appraisal decisions. For example: 

    1. Delete 
    2. Review for deletion
    3. Review for selection
    4. Review for selection (contains PII)
    5. Select for retention
    6. Select for retention (contains PII)

  11. Create hierarchical set of bookmarks to support archival arrangement:

    1. Fonds title
      1. Series title
        1. Sub-series title
      2. Series title

  12. Create word list based on archival appraisal guidelines.

  13. Use a combination of filters, searching, and browsing to select and organize records for retention. Use labels and bookmarks to facilitate this process.

  14. Use bookmarks to export files and metadata from FTK.

    1. Export files option
    2. Report option

  15. Package files into one or more "bags" that conform to the BagIt specification.

  16. Upload bag(s) to the Libraries' ingest storage.

  17. Transfer bag(s) into digital preservation system.

  18. Process transfer and generate AIPs. 

  19. Delete local backup data and FTK case after successful generation of AIPs.

Forensic processing (large cases)

Coming soon.

Workflows at other institutions

Princeton University Library, Department of Rare Books and Special Collections, "Born-Digital University Archives Workflows." https://rbsc.princeton.edu/workflows/born-digital/university-archives. 


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