US Patent 9288211 Providing access control for public and private document fields

A computer generates a modified list of search terms by adding synonyms of the search terms and terms that are related to the search terms to a list of search terms. The computer removes frequently used words from the modified list of search terms. The computer responds to a determination that a user has authorization to view a field of a document by adding to the modified list of search terms an encrypted version of a search term included in a list of search terms. A search using the modified list of search terms returns a result that identifies the document as a search result when either the unencrypted or the encrypted version of the search term is found in a list of index terms associated with the first document.