What is Digital Forensics?

Restoring the truth of an incident falls within the scope of digital forensics

Digital forensics refers to the process of investigating and analyzing digital information devices using rigorous procedures and technological methods to reconstruct the truth of an event. Whether for businesses or individuals, properly handling digital evidence is crucial when dealing with information-related incidents.

With the interplay between technology and law, many cybercrimes and intellectual property infringement cases leave digital footprints. The core task of digital forensics is to utilize technological means to correctly collect and analyze digital evidence while ensuring its admissibility in legal proceedings.

The general process of digital forensics includes:
1. Identify potential locations of digital evidence.
2. Collect data while ensuring the integrity of evidence.
3. Preserve original data following strict procedures.
4. Analyze the data to extract relevant evidence.
5. Present the findings in a forensic report.

Scope of Digital Evidence

Digital evidence exists in a wide range of sources—any electronic device that retains usage records is a potential target for forensic analysis.

Examples of potential sources of digital evidence include:

  • Personal Devices: Mobile phones, USB drives, digital photo albums, etc.
  • Computing Devices: Desktop computers, laptops, industrial PCs, etc.
  • Network Equipment: Firewalls, routers, switches, etc.
  • Server Systems: Large-scale systems such as AIX, Solaris, etc.
  • Storage Media: Optical discs, magnetic tapes, NAS (Network-Attached Storage), etc.

Digital Evidence Imaging

To ensure the integrity of original evidence, digital forensics involves creating an image file (forensic duplicate) of the raw data. This duplicate must be identical to the original data and is verified using cryptographic hash functions such as MD5 or SHA1 to confirm its integrity.

Deleted Data Recovery

Even if a file has been deleted, its data often remains on the storage device. Digital forensics techniques can effectively recover such data. By analyzing unallocated areas, forensic specialists can often retrieve lost files under most circumstances.

Searching for Digital Evidence

Searching for digital evidence is a crucial aspect of forensic analysis.

This process involves:

  • Keyword Matching: Encoding keywords and comparing them against disk data to locate relevant information.
  • Indexing: Creating an index of words or phrases to speed up search operations, including searching within unallocated areas to uncover hidden data.

Digital Evidence Viewing

A high-quality forensic tool should provide comprehensive viewing capabilities for various file formats and multimedia content. This enables forensic analysts to efficiently examine and interpret data, improving the accuracy and efficiency of digital forensic investigations.