# Digital Signatures

> Sign PDF and PDF/A documents with TX Text Control .NET Server: certificates, signature fields, PAdES, RFC 3161 timestamps, several signers and validation.

- **Product:** TX Text Control .NET Server
- **Section:** Documentation
- **Kind:** Topic
- **Path:** TX Text Control .NET Server > Digital Signatures
- **Web URL:** https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/
- **LLMs URL:** https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/llms.txt
- **LLMs-Full URL:** https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/llms-full.txt

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## On This Page

- [How Signing Works in TX Text Control](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/#how-signing-works-in-tx-text-control)
- [Find the Right Page](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/#find-the-right-page)
- [Where to Start](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/#where-to-start)
- [Related Sections](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/#related-sections)

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## In This Section

- [Certificate-Based Signatures](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/certificate-based/llms.txt): Sign PDF documents with X.509 certificates: requirements, DigitalSignature, PFX data, the Windows certificate store, Azure Key Vault and certificate checks.
- [Multiple Signatures](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/multiple/llms.txt): Sign all signature fields of a PDF in one save: a DigitalSignature per field, several certificates and timestamps, sequential signers in the Document Viewer.
- [Overview](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/overview/llms.txt): Integrity and authenticity of signed PDFs explained: signing versus encryption, electronic versus digital signatures, DigitalSignature and server workflows.
- [PAdES](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/pades/llms.txt): PAdES signature profiles for PDF documents: PAdES-B and PAdES-T, what TX Text Control creates, eIDAS signature levels, PDF/A and checking signed documents.
- [Self-Signed Certificates](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/self-signed/llms.txt): Create self-signed test certificates for PDF signatures with PowerShell, OpenSSL or Acrobat Reader, use them in your project and move to CA certificates.
- [Signature Fields](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/signature-fields/llms.txt): Create, read and sign signature fields with ServerTextControl: SignatureField, positions, SignatureImage, SignerData, MS Word signature lines and PDF output.
- [Signing PDF Documents](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/signing/llms.txt): Sign the whole PDF or PDF/A document with DigitalSignature and SaveSettings: merged documents, byte arrays, ASP.NET Core, errors and what happens after signing.
- [RFC 3161 Timestamps](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/timestamps/llms.txt): Add trusted RFC 3161 timestamps to PDF signatures: time-stamping authorities, the timeServerURL parameter, InvalidTimeServer errors and signature fields.
- [Signature Validation](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/validation/llms.txt): Validate the signatures of PDF documents with TXTextControl.PDF.Validation: signature diagnostics, what they check, rejecting uploads and testing tampering.

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## Nearby

- **Previous:** [PDF Validation](https://docs.textcontrol.com/tx-text-control-dotnet-server/pdf/validation/llms.txt)
- **Next:** [Overview](https://docs.textcontrol.com/tx-text-control-dotnet-server/digital-signatures/overview/llms.txt)