A Hierarchical Extraction Policy for Content Extraction Signatures

Content Extraction Signatures (CES), enable the selective extraction of verifiable content, from signed documents. Extending this ability, we introduce a new Hierarchical Grouping Extraction Policy that is more powerful and less costly than the existing Grouping Extraction Policy, and maps naturally onto the hierarchically structured documents commonly found in Digital Libraries. We also show how to implement. the new Extraction Policy using XML Signatures with a custom transform. We introduce an improved design for the XML Signature structure in order to achieve CES functionality. We then conjecture as to how to enrich Digital Library functionality through the use of Content Extraction Signatures.