Long-Term Validation (LTV) for Digital Signatures in Adobe Acrobat

Long-Term Validation (LTV) for Digital Signatures in Adobe Acrobat

Introduction

Long-Term Validation (LTV) ensures that digital signatures remain verifiable over time by embedding status information (e.g., OCSP or CRL data) into the signed document. This guide explains how to properly configure the LTV function in Adobe Acrobat to meet compliance standards, such as the EU’s eIDAS regulation.

Step-by-Step Guide to Enable LTV in Adobe Acrobat

  1. Open Adobe Acrobat Preferences

    • Launch Adobe Acrobat.
    • Go to Edit > Preferences > Signatures.

  2. Configure LTV and Signing Format

    • Under Creation and Appearance Preferences, set the following options:
      • Default Signing Format: CAdES-Equivalent (recommended EU standard).
      • Check the box: "Include signature's revocation status".

    Adobe Screenshot

  3. Ensure Internet Connectivity

    • Make sure your system is connected to the internet during the signing process.
      Without an internet connection, the status information cannot be embedded automatically.
    • If the LTV information could not be embedded during signing, you can add it afterward:
      • Open the document → Validate Signature > Embed LTV Information.

Adding Timestamp to Signatures

To ensure compliance and improve verifiability, add a timestamp to your digital signature:

  1. Go to Edit > Preferences > Signatures > Document Timestamping.
  2. Configure a Timestamp Server:
    • Click on More... and add your qualified Timestamp Authority (TSA) URL.
    • Ensure proper credentials are set up for the server.

Important Note on Certificate Management

  • Do not manually add qualified certificates or CA certificates to Adobe Acrobat’s certificate store.
  • Adobe automatically recognizes qualified certificates.
  • Manually adding certificates can result in inconsistent behavior, where signatures might appear differently for other users.