1. A system, comprising: a data structure populated 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; a filter component configured to identify individual documents that cannot match individual database members using the co-occurrences identified in the data structure; a verification component configured to receive a remainder of the documents and to verify whether sub-strings of the remainder of the documents match the individual database members; and at least one computing device configured to execute one or more of the filter component or the verification component.