---
title: "signing"
canonical_url: "https://www.nutrient.io/api/csharp/signing/"
md_url: "https://www.nutrient.io/api/csharp/signing.md"
last_updated: "2026-10-08T08:55:57.713Z"
description: "Nutrient .NET SDK API reference for signing."
---

Types grouped under `signing` in the API reference. Import them from the `Nutrient` namespace.

```csharp

using Nutrient;

```

## Classes

| Class                                                     | Description                                                                                                                                                                                                                                      |
| --------------------------------------------------------- | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------ |
| [`DigitalSignatureOptions`](./digital-signature-options/) | Options for creating a digital signature on a PDF document.                                                                                                                                                                                      |
| [`Pkcs11Options`](./pkcs11-options/)                      | Locates the signing key on a PKCS#11 (Cryptoki) module — a hardware security module, USB token, or smartcard accessed through a vendor driver.                                                                                                   |

| [`Signature`](./signature/)                               | Provides functionality for signing PDF documents. Supports both digital signatures (with certificate) and electronic signatures (visual only).                                                                                                   |
| [`SignatureAppearance`](./signature-appearance/)          | Defines the visual appearance of a signature in a PDF document. Used for both digital signatures (with certificate) and electronic signatures (visual only).                                                                                     |
| [`TimestampConfiguration`](./timestamp-configuration/)    | Configuration for adding a trusted timestamp to a digital signature. When configured, the signature will include a timestamp from a Time Stamp Authority (TSA), enabling PAdES-T (PDF Advanced Electronic Signatures with Timestamp) compliance. |

---

## Related pages

- [Digital Signature Options](/api/csharp/signing/digital-signature-options.md)
- [Pkcs11 Options](/api/csharp/signing/pkcs11-options.md)
- [Signature Appearance](/api/csharp/signing/signature-appearance.md)
- [Signature](/api/csharp/signing/signature.md)
- [Timestamp Configuration](/api/csharp/signing/timestamp-configuration.md)