What is a bitstream image?

A bitstream image is defined as a sector-by-sector copy of a storage device. This means that every sector on the storage medium, regardless of whether it contains data that appears to be valid or contains deleted information, is copied exactly as it exists. This comprehensive duplication ensures that forensic examiners have access to all the information on the device, including hidden, deleted, or fragmented files, as well as the free space and unallocated areas of the disk.

This method of imaging is crucial in digital forensics because it preserves the original data structure and allows for thorough analysis later on. It enables forensic specialists to conduct investigations with a complete set of data, avoiding the risk of losing any critical evidence that may be present in the unallocated or deleted portions of a device. In the forensic process, maintaining the integrity of the data through a bitstream image is vital for legal and investigative purposes, as it ensures authenticity and reliability in court cases.