Multimedia forensics is a societally important and technically challenging researcharea that will need significant effort for the foreseeable future. While the researchcommunity is growing and work like that in this book demonstrates significantprogress, many challenges remain. We expect that forensically tackling ever-improving media acquisition and generation methods and countering the pace ofchange in media manipulation will continue to require significant technical break-throughs in defensive technologies.Whether performed at the individual level or class level attribution is at the heartof multimedia forensics. This form of passive forensic analysis exploits traces intro-duced by the acquisition or generation pipeline and subsequent editing. These tracesare often subtle and invisible to humans but can be detected currently by analysisalgorithms and provide mechanisms by which generation or manipulation can beautomatically detected. Despite significant achievements in this area of research,advances in imaging technologies and newly introduced approaches to media syn-thesis have a strong potential to render existing forensic capabilities ineffective.