Does SharePoint Portal Server support document encryption?
SharePoint Portal Server 2003/Microsoft Office SharePoint Server 2007 can be configured to leverage Rights Managenent Service (RMS) which allows for the encryption of documents through RMS policy each time a document is requested from a Document Library, the RMS policy will be applied to documents whether they are requested through the Office client, WebDav or FrontPage - RPC.
* While SQL Server 2005 supports certificate-based encryption within the store, encryption will have to be manually implemented through stored procedures using the new SQL Server 2005 TSQL support and technologies for certificate management and encryption. As a result, a SharePoint Portal Server implementation of these technologies is not supported.
Are encrypted documents indexed?
Windows RMS will provide the capability to envelope e-mail and Office Documents that provide limitations as to what actions a user can perform against that file through Information Rights Management (IRM) in Microsoft Office 2003 in addition to adding the capacity to add document expiration, check-in limitations, and more. For additional information surrounding IRM I recommed visiting: http://office.microsoft.com/en-gb/assistance/HA011401841033.aspx. In Microsoft Office SharePoint Server 2007 server integration with RMS and integration with other RMS systems permits policies set on Document Libraries to apply to files that have left the site; with this in mind, the immediate benefit results in the content within the Document Library to be indexed by Microsoft Office SharePoint Server 2007.
Before you can leverage RMS and IRM you must deploy an RMS system in your environment; for additional information on planning and deployment of an RMS system, visit http://technet2.microsoft.com/windowsserver/en/technologies/featured/rms/default.mspx.