Why is Metadata Access Control (MAC) data unreliable as primary forensic evidence?

Metadata Access Control (MAC) data is considered unreliable as primary forensic evidence primarily because it can be easily modified by users. This characteristic undermines the integrity and credibility of MAC data in a forensic context. Since users have the capability to alter metadata on files—such as timestamps indicating when a file was created, last modified, or accessed—this manipulation can lead to challenges in establishing a reliable timeline or definitive evidence in an investigation.

While the other statements touch upon aspects of metadata reliability, they do not capture the critical issue of user modification. Although file properties may change—making them less reliable over time—and different systems can interpret metadata inconsistently, the fact that users can directly modify the metadata significantly impacts its use in legal scenarios where unaltered evidence is crucial. Access to metadata does not solely reside with the operating system; certain applications and user permissions can also grant access, but this does not negate the primary concern of potential user tampering.