Signing in Microsoft Office 2007 Documents
CoSign enables one to add digital signatures, as well as graphical signatures, to .docx and .xlsx Office 2007 documents using a special plug-in called ARX Signature Line Provider. The basic signing process consists of placing signature place-holders (or signature fields) in the desired locations in the document, and signing each field. After signing, one can validate the signatures. Validation assures one that the document was not modified after it was signed and that a trusted CA approved the signers' certificates.