MPEG-21提供了一个框架，将多媒体的许多元素结合在一起。特别是，内容的编码表示与元数据描述符和应用于内容的IPMP保护并列。这就需要能够在MPEG-21中创建和维护（例如，检测或提取）内容、元数据和IPMP元素之间的关联的工具。 ISO/IEC TR 21000-11:2004描述了两类技术的评估方法，这两类技术可以创建和维护此类关联:“水印”和“指纹”，适用于音频内容。

MPEG-21 provides a framework within which many elements of multimedia are brought together. In particular, coded representations of content are juxtaposed with metadata descriptors and IPMP protection that apply to the content. This leads to a requirement for tools that can create and maintain (e.g. detect or extract) an association between content, metadata and IPMP elements within MPEG-21. ISO/IEC TR 21000-11:2004 describes methodologies for the evaluation of two classes of technologies that can create and maintain such associations: "watermarks" and "fingerprints", when applied to audio content.