Which action is described as the important first step in digital forensics to ensure that data is not changed?

• A. Making a bit-to-bit ratio copy
• B. Deleting original data
• C. Overwriting the drive
• D. Taking a screenshot

Answer: (A)

In digital forensics, the first priority is to preserve the evidence exactly as it exists. That means creating a forensically sound copy of the storage device that is bit-for-bit identical to the original. This is accomplished by imaging the drive with a write blocker in place so no data can be written to the source during the process. By capturing every bit, you preserve all data, including deleted files, unallocated space, and metadata that could be crucial to the investigation.

This approach lets you later verify integrity by comparing cryptographic hashes of the original and the copy, ensuring the copy is a true, unaltered replica. It also allows analysts to work on the copy rather than the original, maintaining the chain of custody and keeping the original pristine for potential future scrutiny.

Other actions would compromise the evidence. Deleting the original would erase information that might be needed; overwriting the drive would destroy data on the source; a screenshot doesn’t capture the full content of the storage and could be incomplete or misleading.