Assign and Validate Digital Signatures

A digital signature provides assurance that a workbook file is valid and no one has altered it. You can create a personal digital signature by using the Microsoft Selfcert.exe or any other tool, or you can purchase a digital signature. After you create a digital signature, you must attach it to your workbook. Attaching a digital signature is similar to sealing an envelope. If an envelope arrives sealed, you have some level of assurance that no one has tampered with its contents.

Introduction

Use the Digital Signature dialog to attach a digital signature. The Digital Signature dialog lists valid certificates. You can use the Digital Signature dialog to view certificates and to select the one you want to use. If a workbook has a digital signature, the name of the signature appears in the Certificate Name field. If you click the Remove button in the Digital Signature dialog, Microsoft Excel removes the digital signature as well.

How to Add Digital Signature for Excel

Aspose.Cells provides the Aspose.Cells.DigitalSignatures namespace to perform the job (assign and validate digital signatures). The namespace has some useful features for adding and validating digital signatures.

Please see the following sample code that describes how you can perform the task using the Aspose.Cells for .NET API.

Advance topics

• Add Digital Signature to an already signed Excel file
• Add Signature line to the worksheet
• Support for XAdES Signature