Meaning
Creating an exact copy of the contents of a digital storage device allows for the preservation of evidence in its original state. This forensic imaging process captures every bit of data, including hidden files, temporary folders and deleted items that are not visible through a standard file browser. It is the standard method for securing digital information for use in an investigation or a dispute.
Preservation Method
Securing a device and creating a bit-stream copy prevents the accidental or intentional alteration of the data. This method is used when there is a risk that evidence might be destroyed or modified. The resulting image is a static record of the device at a specific point in time, which can be analyzed without changing the original source.
Digital Integrity
Verification of the copy is performed using a mathematical hash to prove that it is identical to the original. This integrity check ensures that the evidence has not been tampered with during the imaging process. It provides a high level of confidence in the results of any subsequent analysis of the files.
Evidentiary Weight
Evidentiary value relies on proper imaging techniques to ensure digital records are found reliable and admissible during a dispute. An image that is created using professional tools carries more weight than a simple copy-and-paste of files because it preserves the metadata, the file structure, the temporary files and the empty space on the drive. It allows an investigator to reconstruct the history of a device, the timing of file deletions and the actions of its user with a high degree of precision.
This level of detail is often the only way to prove whether a specific document existed or was modified at a critical moment in the life of the company.