---
title: "Digital signature: Sign and certify a PDF | Nutrient .NET SDK"
canonical_url: "https://www.nutrient.io/guides/dotnet/signatures/"
md_url: "https://www.nutrient.io/guides/dotnet/signatures.md"
last_updated: "2026-05-21T17:12:02.219Z"
description: "Learn the secrets to enhancing your document security with advanced digital signatures in .NET. Master the art of secure data signing now!"
---

# Digital signatures in C# .NET

PDF documents often require signatures for authentication purposes, and the use of electronic and digital signatures in PDFs has become increasingly common in recent years. Signatures in PDFs enable individuals and organizations to sign documents electronically, eliminating the need for physical signatures and making it more efficient to conduct business. In this context, signatures in PDFs can provide security, authenticity, and integrity to documents and help streamline the document-signing process.

Nutrient.NET SDK (formerly GdPicture.NET) provides the means to create and modify signature fields. The full range of specialized methods enables you to sign a document with text, an image, or a combination of both. You can also get the details of a signature in a signed PDF document.

## Key capabilities

- **Sign with a digital signature** — Add and customize digital signatures

- **Different certificate sources** — Add certificates from multiple sources

- **Get signature details** — Get all signature details from signed PDF documents

- **Add signature fields** — Add signature fields and get their properties

- **Multi-signature support** — Handle documents with multiple signatures and fill multiple signatures

## Guides for PDF signatures

**[Digital signatures](https://www.nutrient.io/guides/dotnet/signatures/digital-signatures/add-a-digital-signature.md)**\
How to sign with a digital signature

**[Certify a document](https://www.nutrient.io/guides/dotnet/signatures/digital-signatures/certify-a-document.md)**\
How to add certificates to a PDF document

**[Add signature fields](https://www.nutrient.io/guides/dotnet/signatures/signature-field/add-a-signature-field.md)**\
How to add signature fields

**[Fill signature fields](https://www.nutrient.io/guides/dotnet/signatures/signature-field/fill-a-signature-field.md)**\
How to fill a signature field

**[Get signature field properties](https://www.nutrient.io/guides/dotnet/signatures/signature-field/get-signature-field-properties.md)**\
How to get a signature field’s properties
---

## Related pages

- [Add an ink eSignature in C#](/guides/dotnet/signatures/add-an-ink-esignature.md)
- [Introduction to signatures in C#](/guides/dotnet/signatures/introduction.md)

## Pages in this section

- [Remove a signature field from a PDF in C#](/guides/dotnet/signatures/signature-field/remove-signature-field.md)
- [Fill and sign PDFs in C# .NET](/guides/dotnet/signatures/signature-field/fill-a-signature-field.md)
- [Get signature field properties in C#](/guides/dotnet/signatures/signature-field/get-signature-field-properties.md)
- [Add a signature field to a PDF in C#](/guides/dotnet/signatures/signature-field/add-a-signature-field.md)
- [Sign PDF documents with a certificate in C#](/guides/dotnet/signatures/digital-signatures/certify-a-document.md)
- [Add a digital signature to a PDF in C#](/guides/dotnet/signatures/digital-signatures/add-a-digital-signature.md)
- [Create a self-signed certificate with PADES extensions](/guides/dotnet/signatures/digital-signatures/sign-a-docx-as-pdf-ua.md)
- [Create a self-signed certificate with PADES extensions](/guides/dotnet/signatures/digital-signatures/sign-a-pdf-ua-document.md)