We use cookies to give you the best experience on our website. If you continue to browse, then you agree to our privacy policy and cookie policy. Image for the cookie policy date
Unfortunately, activation email could not send to your email. Please try again.
Syncfusion Feedback

Trusted by the world’s leading companies

Syncfusion Trusted Companies


PDF digital signature and timestamp are the best ways to protect your PDF files from being forged. Syncfusion Essential PDF is a .NET Core PDF library that helps you add digital signature and time stamp to your PDF files in any .NET Core application.

Syncfusion provides many ways to digitally sign a document: X509 certificates, such as .pfx files with private keys and also supports hardware security modules (HSM), Online Certificate Status Protocol (OCSP), certificate revocation lists (CRL), and Windows Certificate Store for authenticity and integrity.

Customize Appearance

The Syncfusion .NET Core PDF library provides a completely customizable appearance for its e-signature. The content of the signature can be images, texts, graphics, and shapes.

Custom Appearance


Long-Term Validation (LTV)

LTV signatures allow you to check the validity of a signature long after signing the document. All the required elements for signature validation must be embedded in the signed PDF to use LTV.

Timestamp PDF

It is possible to include the date and time of your signing the PDF as part of your certificate-based digital signature. A timestamp helps you establish when you signed the PDF and reduces the chance of an invalid signatures. Syncfusion Essential PDF makes time-stamping a PDF document possible with only a few lines of code.


Certificate details

Certificate Details

You can also get or retrieve the digitally signed certificate details like subject, author, and expiry date. Based on the expiry date, you can digitally sign the PDF with valid certificate again.

Additional features of digital signatures and timestamps

  • Sign existing PDFs with digital signatures.
  • Add multiple digital signatures to a PDF.
  • Add signature validation to a PDF.
  • Time-stamp an existing PDF document.
  • Time-stamp a PDF without a certificate.

PDF Digital Signature Code Example

Easily add the digital signature to a PDF document using a few simple lines of C# code as demonstrated below. Also explore our .NET Core PDF Example that shows how to create and modify PDF files from C# with 5 lines of code on different platforms.

using Syncfusion.Pdf;

//Creates a new PDF document

PdfDocument document = new PdfDocument();

//Adds a new page

PdfPageBase page = document.Pages.Add();

PdfGraphics graphics = page.Graphics;

//Creates a certificate instance from PFX file with private key

PdfCertificate pdfCert = new PdfCertificate(@"PDF.pfx", "syncfusion");

//Creates a digital signature

PdfSignature signature = new PdfSignature(document, page, pdfCert, "Signature");

//Sets an image for signature field

PdfBitmap signatureImage = new PdfBitmap(@"signature.jpg");

//Sets signature information

signature.Bounds = new RectangleF(new PointF(0, 0), signatureImage.PhysicalDimension);

signature.ContactInfo = "johndoe@owned.us";

signature.LocationInfo = "Honolulu, Hawaii";

signature.Reason = "I am author of this document.";

//Draws the signature image

graphics.DrawImage(signatureImage, 0, 0);

//Saves and closes the document

MemoryStream stream = new MemoryStream();


Imports Syncfusion.Pdf

'Creates a new PDF document

Dim document As New PdfDocument()

'Adds a new page

Dim page As PdfPageBase = document.Pages.Add()

Dim graphics As PdfGraphics = page.Graphics

'Creates a certificate instance from PFX file with private key

Dim pdfCert As New PdfCertificate("PDF.pfx", "syncfusion")

'Creates a digital signature

Dim signature As New PdfSignature(document, page, pdfCert, "Signature")

'Sets an image for signature field

Dim signatureImage As New PdfBitmap("signature.jpg")

'Sets signature info

signature.Bounds = New RectangleF(New PointF(0, 0), signatureImage.PhysicalDimension)

signature.ContactInfo = "johndoe@owned.us"

signature.LocationInfo = "Honolulu, Hawaii"

signature.Reason = "I am author of this document."

'Draws the signature image

graphics.DrawImage(signatureImage, 0, 0)

'Saves and closes the document

Dim stream As MemoryStream = New MemoryStream()





Syncfusion’s file format components helped me create the reports I needed, fast. – J. Pereira, Software Developer.

The libraries have been built from scratch and refined for more than a decade to provide blazing-fast performance, comprehensive API, and compatibility across the latest and older versions of these files.

CONTINUE READING View all Customer Stories


Syncfusion File Format Libraries - Manipulate Excel, Word, PowerPoint, and PDF files

Read and write Excel, Word, PDF, and PowerPoint files. Also includes integrated visualization capabilities. Advanced features include support for pivot tables, pivot charts, mail-merge, and extensive formatting.


Succinctly Series: Statistics Using Excel Succinctly

Succinctly Series: Statistics Using Excel Succinctly

- by Charles Zaiontz


Greatness—it’s one thing to say you have it, but it means more when others recognize it. Syncfusion is proud to hold the following industry awards.

Scroll up icon

Warning Icon You are using an outdated version of Internet Explorer that may not display all features of this and other websites. Upgrade to Internet Explorer 8 or newer for a better experience.Close Icon

Live Chat Icon For mobile
Live Chat Icon