InfoPath Dev

I have an info path document that submits to a document library. The first step in my workflow, once the new document is submitted, is to verify there is a digital signature on the form, then email the submitter back a copy of another document that is in another document library.   I can set a URL to the library and have them get it ...

We have found that the digital signature issue is due to the IUSR account being in the guest group on the certificate server.  We removed it from the local security policy guest group and viola! our browser forms worked great.  The cert server uses the IUSR account to be able to confer between the form and the certificate.

I have a repeating table in a form and wanted to have each line item of the table be signed when it was filled in, because different people would be filling in the lines. Can I do that?  if so, how? Thanks