Factors Affecting One-Way Hashing of CD-R Media

While conducting a validation study of proficiency test media we found that applying the same hash algorithm against a single CD using different forensic applications resulted in different hash values. We formulated a series of experiments to determine the cause of the anomalous hash values. Our results suggest that certain write options cause forensic applications to report different hash values. We examine the possible consequences of these anomalies in legal proceedings and provide best practices for the use of hashing procedures