> For the complete documentation index, see [llms.txt](https://docs.apryse.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://docs.apryse.com/xamarin/digital-signature.md). # Digital signature - [Xamarin Digital Signature Library](https://docs.apryse.com/xamarin/digital-signature/signature.md): Easily sign, certify, and verify digital signatures in PDF documents with our built-in certificate parsing tool. Learn how to add long-term validation and customize signature handling for enhanced sec - [Add a DocTimeStamp signature in Xamarin](https://docs.apryse.com/xamarin/digital-signature/signature/dts.md): Set doctimestamp in PDF in Xamarin to add authenticity to the document. Learn how to add trusted certifictae using WebViewer. - [Custom Signing in Xamarin](https://docs.apryse.com/xamarin/digital-signature/signature/custom-signing.md): Discover how the Apryse custom signing API simplifies document signing with cryptographic digital signatures. Integrate PDF-specific operations effortlessly with access to HSM tokens, cloud keystores, - [Embedded Timestamp Tokens with custom signing API in Xamarin](https://docs.apryse.com/xamarin/digital-signature/signature/emb-tst.md): Learn how to create and insert secure timestamp tokens with the custom signing API. Ensure PAdES-format signature conformance by adding trusted root certificates for verifiability. Enable online CRL r - [Types of digital signatures supported in a PDF](https://docs.apryse.com/xamarin/digital-signature/signature/sig-types.md): Learn about the different types of signatures supported in a PDF document - Certification, Usage Rights, and Approval signatures. Explore the Apryse SDK for working with digital signatures as per the - [Verify a signature in Xamarin](https://docs.apryse.com/xamarin/digital-signature/signature/verify-pdf.md): We offer a higher-level document-based API for verifying signatures, as well as a lower-level per-signature API. Page includes code samples. - [Add Long-Term Validation (LTV) information for a signature in Xamarin](https://docs.apryse.com/xamarin/digital-signature/signature/ltv.md): Learn how to enable LTV to digital signature in PDF either signed internally or externally in {{language}}. - [Sign a PDF document in Xamarin](https://docs.apryse.com/xamarin/digital-signature/sign-pdf.md): Learn how to digitally sign PDF files with the Apryse SDK. Add approval signatures using a Digital Certificate for authenticity and security. Get a full code sample for signing PDF documents. The Apry - [Digital Signature Tool](https://docs.apryse.com/xamarin/digital-signature/digi-sig-tool.md): Learn how to add digital signatures in Xamarin.Android using the Apryse SDK. Enable certificate-based signatures with UI components for secure document signing. The Apryse Xamarin SDK streamlines secu - [Digital Signature Validation in Xamarin](https://docs.apryse.com/xamarin/digital-signature/digital-signature-validation.md): Validate signatures in signed documents by verifying signers with the DigitalSignatureListDialog. View signer's name, time of signing, validity, and more. Tap on Signature Properties for additional de - [Adding a certified signature field to a PDF in Xamarin](https://docs.apryse.com/xamarin/digital-signature/certify-pdf.md): Learn how to add a certification signature field to a PDF document and digitally sign it with full code samples. Certify PDF files easily using the digital signature API. The Apryse Xamarin SDK stream - [Code samples for adding digital signatures to PDFs in Xamarin](https://docs.apryse.com/xamarin/digital-signature/samples.md): Digitally sign PDF files with ease using our high-level API. Explore UI samples and showcase features in our Xamarin.Android demo app. Try out the signature demo now! The Apryse Xamarin SDK streamline - [API for digital signatures in Xamarin](https://docs.apryse.com/xamarin/digital-signature/apis.md): Learn how to handle digital signatures in PDF documents with classes like pdftron.SDF.SignatureHandler and pdftron.PDF.DigitalSignatureField in Xamarin.Android and Xamarin.iOS using C#. The Apryse Xam --- # Agent Instructions This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. 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