What method of copying should always be performed first before carrying out an investigation?

What method of copying should always be performed first before carrying out an investigation?

• A. Parity-bit copy
• B. Bit-stream copy
• C. MS-DOS disc copy
• D. System level copy

Answer: (B)

Bit-for-bit copying is the essential first step because it creates a perfect replica of the entire storage device, capturing every bit of data, including deleted information, slack space, and the master boot record. This exact image preserves the original evidence in a form that can be analyzed later without altering the source, which is crucial for maintaining integrity and admissibility in investigations. After making the bit-stream copy, you can hash the image to prove it’s identical to the original and establish a verifiable chain of custody. Other methods don’t guarantee a complete or unaltered copy. A parity-bit approach isn’t a standard, reliable method for forensic imaging and won’t ensure a true bit-for-bit replica. An MS-DOS disc copy is not designed for forensic preservation and can modify file system metadata or omit unallocated space. A system-level copy might miss hidden sectors or metadata and can change timestamps, undermining the evidence’s integrity. Bit-stream imaging with a write blocker is the trusted practice to ensure the original remains untouched while you work from the exact copy.

Bit-for-bit copying is the essential first step because it creates a perfect replica of the entire storage device, capturing every bit of data, including deleted information, slack space, and the master boot record. This exact image preserves the original evidence in a form that can be analyzed later without altering the source, which is crucial for maintaining integrity and admissibility in investigations. After making the bit-stream copy, you can hash the image to prove it’s identical to the original and establish a verifiable chain of custody.

Other methods don’t guarantee a complete or unaltered copy. A parity-bit approach isn’t a standard, reliable method for forensic imaging and won’t ensure a true bit-for-bit replica. An MS-DOS disc copy is not designed for forensic preservation and can modify file system metadata or omit unallocated space. A system-level copy might miss hidden sectors or metadata and can change timestamps, undermining the evidence’s integrity. Bit-stream imaging with a write blocker is the trusted practice to ensure the original remains untouched while you work from the exact copy.