DigitalSignature

using System;
using System.Collections.Generic;
using System.Text;
using Bytescout.PDF;
namespace DigitalSignature
{
  class Program
  {
    static void Main(string[] args)
    {
      // Create main PDF Doc Engine
      PDFDocEngine engine = new PDFDocEngine("", "");
      // Open existing document
      Document document = engine.AddDocument("HelloWorld.pdf");
      document.AddSignature(@"c:\dig-signature.pfx", "John Doe", "Only for test...", false, "123456");
      // Save document
      document.Save("signed.pdf");
    }
  }
}