9. A method comprising: populating a data structure with document tokens selected from signatures of documents and member tokens selected from database members, the data structure including entries identifying co-occurrences of the document tokens and the member tokens; identifying individual documents that cannot match individual database members using the co-occurrences identified in the data structure; receiving a remainder of the documents; and verifying whether sub-strings of the remainder of the documents match the individual database members.
9. A method comprising: populating a data structure with document tokens selected from signatures of documents and member tokens selected from database members, the data structure including entries identifying co-occurrences of the document tokens and the member tokens; identifying individual documents that cannot match individual database members using the co-occurrences identified in the data structure; receiving a remainder of the documents; and verifying whether sub-strings of the remainder of the documents match the individual database members. 13. The method of claim 9 , wherein the data structure comprises an inverted signature-based hashtable.