I-Corps: Development of an Audio Forensic Analysis Tool

数字多媒体（图像、音频和视频）作为证据的使用在包括法律诉讼和执法在内的多种公民应用中迅速增长。验证数字证据的真实性和完整性是一项复杂且具有挑战性的任务，因为数字信息可以使用广泛可用的编辑工具轻松复制和更改。特别是，在没有辅助数据（即数字水印）的情况下，如果唯一的输入是媒体本身，身份验证就会给数字取证带来独特的问题。到目前为止，现有的先进技术还无法唯一地将给定的数字录音与“麦克风”联系起来，将音频录音与录制地点联系起来，也无法检测到反法医处理的痕迹。所提出的音频法医分析工具使法医分析人员能够对基本的法医调查问题提供权威的答案。该项目旨在展示音频法医分析工具的有效性，该工具能够检测数字录音中的伪造内容。所提出的工具依赖于声学线索、麦克风非线性痕迹和数字音频记录中留下的后处理伪影。所提出的工具使用统计数据建模和特征提取技术来捕获这些指纹，并使用它们将给定的记录与“采集”设备和“声学”环境联系起来。该团队认为，所提出的音频取证分析工具，一旦成功商业化，可以为法医审查员、传统媒体、新闻媒体、社交媒体和执法人员提供一个非常强大、计算效率高、可扩展和可靠的工具，用于执行在线（以及离线）取证分析，以确定数字媒体对象的真实性，并在数字媒体对象中定位伪造（如果有的话）。

The use of digital multimedia (images, audio, & video) as evidence is rapidly growing in multiple civic applications, including legal proceedings and law enforcement. Verifying the authenticity and integrity of digital evidence is a complex and a challenging task given the ease with which digital information can be copied and altered using widely available editing tools. In particular, in the absence of helping data (i.e., digital watermarks) and if the only input is the media itself, authentication poses unique problems for digital forensics. Until now existing state-of-the-art is unable to uniquely link a given digital recording to "the" microphone, link an audio recording to the location it was made, or detect traces of anti-forensic processing. The proposed audio forensic analysis tool enables a forensics analyst to provide authoritative answers to basic forensic investigation questions. The project aims to demonstrate effectiveness of the audio forensic analysis tool capable to detecting forgeries in digital audio recordings. The proposed tool relies on acoustic cues, microphone nonlinearity traces, and post-processing artifacts left in the digital audio recording. The proposed tool uses statistical data modeling and feature extraction techniques to capture these fingerprints, and use them for linking a given recording to "the" acquisition device and to "the" acoustic environment. This team believes that the proposed audio forensic analysis tool, when successfully commercialized, could provide forensic examiners, traditional media, news outlets, social media, and law enforcement personnel a very powerful, computationally efficient, scalable, and reliable tool to perform online (as well as offline) forensics analysis, to determine authenticity of the digital media object, localize forgery (if any) in the digital media object.