Forensic audio : the relevance of Electric Network Frequency Analysis as an authentication tool in South Africa

dc.contributor.advisorDe Villiers, William Murrayen
dc.contributor.emailtarryn.denton@gmail.comen
dc.contributor.postgraduateDenton, Tarryn-Chevonne Morgaineen
dc.date.accessioned2015-11-25T09:54:03Z
dc.date.available2015-11-25T09:54:03Z
dc.date.created2015/09/01en
dc.date.issued2015en
dc.descriptionMini-dissertation (MMus)--University of Pretoria, 2015.en
dc.description.abstractThe predominance of digital media in modern society has presented a need for methods of authenticating digital audio. When an audio recording is presented as part of legal or business proceedings, it may be necessary to provide proof of authenticity. This minidissertation investigates to what extent Electric Network Frequency (ENF) analysis can be implemented as an authentication technique within a South African context. The electricity supply frequency exhibits random deviations in time from the nominal frequency of 50 Hz. ENF analysis is based on the premise that the supply frequency is detectable in audio recordings made on equipment utilising, or in close proximity to, electrical equipment that utilises the main electrical network. The recorded ENF signal can be extracted and used as a unique temporal identifier for determining the authenticity of an audio recording. Results of experiments conducted in this study indicate that it is possible for a detectable ENF signal to be induced into an audio recording, and subsequently isolated for further analysis. It is possible to compare the extracted ENF signal to the extracted ENF signal from a reliable database to determine temporal authenticity, and investigate the integrity of the file. It is found that the following minimum requirements must be met for successful ENF authenticity analysis: • The recording device be powered by the main electrical network, • The equipment be proven to be suitable for use in ENF analysis, i.e. no UPS device is used; the microphone does not have any electrical components that could alter the ENF signal, and the sound card does not induce any frequency components or noise into the signal; and • The availability of a reliable comparative temporal database of ENF values. Furthermore, results indicate that establishing an ENF temporal database by recording the supply frequency utilising a data acquisition unit, and subsequently processing the signal, is more practical than recording the database as an audio file. It was found that the South African electricity supply is sufficiently random to be suitable for ENF authenticity analysis. Recommendations for further study are made.en
dc.description.availabilityUnrestricteden
dc.description.degreeMmusen
dc.description.departmentMusicen
dc.description.librariantm2015en
dc.identifier.citationDenton, TM 2015, Forensic audio : the relevance of Electric Network Frequency Analysis as an authentication tool in South Africa, Mmus Mini-dissertation, University of Pretoria, Pretoria, viewed yymmdd <http://hdl.handle.net/2263/50875>en
dc.identifier.otherS2015en
dc.identifier.urihttp://hdl.handle.net/2263/50875
dc.language.isoenen
dc.publisherUniversity of Pretoriaen_ZA
dc.rights© 2015 University of Pretoria. All rights reserved. The copyright in this work vests in the University of Pretoria. No part of this work may be reproduced or transmitted in any form or by any means, without the prior written permission of the University of Pretoria.en
dc.subjectUCTDen
dc.subjectElectric Network Frequency (ENF)
dc.subjectDigital Audio Authenticity
dc.subjectForensic Audio
dc.subjectAudio Integrity
dc.subjectAuthentication
dc.subjectDigital Audio Recording
dc.subject.otherMusic theses SDG-09
dc.subject.otherSDG-09: Industry, innovation and infrastructure
dc.subject.otherMusic theses SDG-16
dc.subject.otherSDG-16: Peace, justice and strong institutions
dc.titleForensic audio : the relevance of Electric Network Frequency Analysis as an authentication tool in South Africaen
dc.typeMini Dissertationen

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