| This thesis is an investigative approach to the configuration of Electric Network Frequency (ENF) databases that are built with the intent to provide an accurate, reliable, and reproducible source of electric network frequency variations to be used in scientific research and forensic examinations of digital multimedia. For the ENF Criterion to reach full potential in the United States, forensic best practices, database cross-validations, and widely accepted methodologies should be maintained. This thesis will help guide forensic researchers in configuring ENF databases in a manner that reinforces those goals. Through an investigative approach, various elements of an ENF database are explored. The introduction of this thesis starts with a broad overview of general forensic science, then narrows the focus to defining media forensics, and finishes with background on the ENF Criterion. Chapter two reviews the available scientific literature on the ENF Criterion. Chapter three investigates several elements of an ENF database and explains how they can be used to configure a more robust, reliable, and reproducible forensic ENF database. Chapter four proposes a system of broadcast type ENF databases where ENF is gathered in one location and received in a remote location. Chapter five draws the conclusions. Appendix A describes voltage regulated ENF sources, appendix B outlines a real case application of the proposed ENF database configuration, and appendix C explains why and how ENF works. |
