Workbook.Signatures (Excel)
Returns the digital signatures for a workbook.
To digitally sign Excel workbooks and verify other signatures in them, you will need the Microsoft CryptoAPI and a unique digital signature certificate. The CryptoAPI is installed with Microsoft Internet Explorer 4.01 or later. You can obtain a digital signature certificate from a certification authority.
Dim sstSignatures As Office.SignatureSet
Set sstSignatures = ActiveWorkbook.Signatures