The design and implementation of a prototype digital video watermarking scheme with dynamic traitor tracing

Salotto, Antony (2014-12)

Thesis (MEng)--Stellenbosch University, 2014.

Thesis

ENGLISH ABSTRACT: We design and implement a prototype digital watermarking scheme that uses spread-transform dither modulation to embed hidden binary message signals into uncompressed digital video signals. The hidden messages are intended to identify the original recipient of a particular copy of a digital video, so that in the event that a pirate copy of that video is found, the recipient can be incriminated as a pirate. We test the ability of the watermark signal to survive various modifications to the watermarked video, including lossy compression, frame deletion, and amplitude scaling. We find that the scheme performs well when watermarked videos remain uncompressed, but the scheme is not sufficiently robust against lossy compression. We also implement a dynamic traitor tracing scheme based on the scheme of Fiat and Tassa, which is designed to identify a group of pirates who combine their watermarked videos in an attempt to defeat the watermarking scheme. We test the traitor tracing scheme in a simulated digitally watermarked video broadcast system where a pirate rebroadcast is monitored. We find that when the pirate rebroadcast is delayed, our traitor tracing scheme identifies and disconnects the pirates more quickly than the scheme of Fiat and Tassa.

AFRIKAANSE OPSOMMING: Ons ontwerp en implementeer ’n digitale watermerkskema-prototipe wat strektransform-bibbermodulasie gebruik om binêre boodskapseine in digitale videoseine te verskuil. Die doel van die versteekte boodskappe is om die oorspronklike ontvanger van ’n bepaalde digitale video-afskrif te identifiseer. Indien ’n onwettige afskrif van die video ontdek word, kan die oorspronklike ontvanger daarvoor verantwoordelik gehou word. Ons toets die vermoë van die watermerksein om verskeie veranderinge aan die gewatermerkte video te oorleef, byvoorbeeld kompressie, die verwydering van videorame, en amplitudeskalering. Die skema vaar goed in die afwesigheid van videokompressie, maar is nie robuus wanneer die video beduidend saamgepers word nie. Ons implementeer ook ’n dinamiese skema vir verraaier-opsporing, gebaseer op ’n tegniek deur Fiat en Tassa. Die doel van hierdie skema is om groepe gebruikers te identifiseer wat saamwerk om ’n watermerkskema te kul deur gewatermerkte videos te kombineer. Ons toets die verraaier-opsporingskema in ’n simulasie van ’n gewatermerkte video-uitsendingstelsel wat ’n roofuitsending monitor. Wanneer die roofuitsending vertraag is, vind ons dat die voorgestelde verraaier-opsporingskema die skuldige gebruikers vinniger uitwys as die skema van Fiat en Tassa.

Please refer to this item in SUNScholar by using the following persistent URL: http://hdl.handle.net/10019.1/96068
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