162875-Added README.md files for digital signature samples for Demo list

Digital-Signature/Add-digital-signature-invisible/.NET/Add-digital-signature-invisible/README.md

@@ -0,0 +1,52 @@
+# Add a digital signature in a Word document using C#
+
+The [.NET Word Library](https://www.syncfusion.com/document-sdk/net-word-library) (DocIO) empowers you to create, read, and edit Word documents programmatically without Microsoft Word or interop dependencies. Using this library, you can **add an invisible digital signature to a Word document** using C#.
+
+## Steps to add an invisible digital signature to a Word document programmatically
+
+Step 1: Create a new .NET Core console application project.
+
+Step 2: Install the [Syncfusion.DocIO.Net.Core](https://www.nuget.org/packages/Syncfusion.DocIO.Net.Core) NuGet package as a reference to your project from [NuGet.org](https://www.nuget.org/).
+
+Step 3: Include the following namespaces in the Program.cs file.
+
+```csharp
+using Syncfusion.DocIO;
+using Syncfusion.DocIO.DLS;
+using Syncfusion.Office;
+```
+
+Step 4: Add the following code snippet in Program.cs file to add an invisible digital signature to a Word document.
+
+```csharp
+//Opens an existing Word document.
+WordDocument document = new WordDocument(Path.GetFullPath(@"Data\Template.docx"));
+//Loads the signing certificate from disk.
+OfficeDigitalSignatureCertificate certificate = new OfficeDigitalSignatureCertificate(Path.GetFullPath(@"Data\certificate.pfx"), "password123");
+//Configures signature settings.
+SignatureSettings settings = new SignatureSettings();
+settings.Comments = "Approved";
+settings.SignTime = DateTime.Now;
+//Sets the application version used to create the signature.
+settings.ApplicationVersion = "16.0";
+//Sets the Office version recorded with the signature.
+settings.OfficeVersion = "16.0";
+//Sets the Windows version recorded with the signature.
+settings.WindowsVersion = "10.0";
+//Sets the horizontal resolution recorded with the signature.
+settings.HorizontalResolution = 1920;
+//Sets the vertical resolution recorded with the signature.
+settings.VerticalResolution = 1080;
+//Sets the color depth recorded with the signature.
+settings.ColorDepth = 32;
+//Sets the cryptographic provider identifier.
+settings.ProviderId = new Guid("00000000-0000-0000-0000-000000000000");
+//Adds an invisible digital signature to the document using the certificate and settings.
+document.AddDigitalSignature(certificate, settings);
+//Saves the Word document to file.
+document.Save(Path.GetFullPath(@"Output\Result.docx"), FormatType.Docx);
+//Closes the document
+document.Close();
+```
+
+More information about add a digital signature in a Word document can be refer in this [documentation](https://help.syncfusion.com/document-processing/word/word-library/net/working-with-digital-signature) section.

Digital-Signature/Validate-digital-signature/.NET/Validate-digital-signature/README.md

@@ -0,0 +1,40 @@
+# Validate a digital signature in a Word document using C#
+
+The [.NET Word Library](https://www.syncfusion.com/document-sdk/net-word-library) (DocIO) empowers you to create, read, and edit Word documents programmatically without Microsoft Word or interop dependencies. Using this library, you can **validate digital signatures in a Word document** using C#.
+
+## Steps to validate digital signatures in a Word document programmatically
+
+Step 1: Create a new .NET Core console application project.
+
+Step 2: Install the [Syncfusion.DocIO.Net.Core](https://www.nuget.org/packages/Syncfusion.DocIO.Net.Core) NuGet package as a reference to your project from [NuGet.org](https://www.nuget.org/).
+
+Step 3: Include the following namespaces in the Program.cs file.
+
+```csharp
+using Syncfusion.DocIO;
+using Syncfusion.DocIO.DLS;
+using Syncfusion.Office;
+```
+
+Step 4: Add the following code snippet in Program.cs file to validate digital signatures in a Word document.
+
+```csharp
+//Opens the signed Word document.
+WordDocument document = new WordDocument(Path.GetFullPath(@"Data\SignedDocument.docx"));
+//Gets the digital signature collection in the document.
+OfficeDigitalSignatureCollection signatures = document.DigitalSignatures;
+//Checks whether every digital signature in the collection is valid.
+bool allValid = signatures.IsValid;
+Console.WriteLine("All signatures are valid : " + allValid);
+//Iterates through each signature and checks whether it is valid.
+foreach (OfficeDigitalSignature signature in signatures)
+{
+    //Checks whether the signature is valid.
+    bool isValid = signature.IsValid;
+    Console.WriteLine("Signature is valid : " + isValid);
+}
+//Closes the document
+document.Close();
+```
+
+More information about validate a digital signature in a Word document can be refer in this [documentation](https://help.syncfusion.com/document-processing/word/word-library/net/working-with-digital-signature) section.