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Version: 4.32

How to securely sign PDF with Adobe Acrobat Reader

Overview​

This tutorial guides you through the process of signing a PDF document using a certificate-based digital signature. This documentation is aimed at any Redtrust user. You don't need any prior knowledge to follow this guide.

Background​

A digital signature is a cryptographic mechanism that verifies both the origin and integrity of a document. It uses a digital certificate issued by a trusted Certificate Authority (CA) to confirm the signer’s identity and to ensure that the document has not been altered after signing.

When you apply a digital signature in Adobe Acrobat Reader, the software uses your certificate to create a unique encrypted seal that binds your identity to the document’s content. Any subsequent modification invalidates the signature, providing strong assurance of authenticity and integrity.

Before you start​

To follow this how-to you will need the following:

info

If you are a user without admin privileges, skip step 1 and 3. If you cannot sign the document, contact your admin and ask them to configure step 1.

Step 1: Create a policy for Adobe acrobat​

In this step you, as an admin, create a policy that allows signing with Adobe Acrobat. If you have a policy that allows access to all applications, as mentioned in Step 3 of the initial Redtrust configuration, this policy is not necessary and can skip to step 2.

  1. Access the admin console.
  2. Go to Policies and click New.
  3. In the window:
    1. In the Name field, add a name for the policy, in our example Acrobat. Click Next.
    2. Select the certificate or certificate group you want the policy to apply to, in this example cert_group1. Click Next.
    3. Select the user or user group you want the policy to apply to, in this example user_group1. Click Next.
    4. In the Where? section click Add applications > Add application group.
      1. In the Application group name add PDF signing.
      2. In Process name (without extension) add acrobat and click Add and Apply.
    5. Select Anytime and click Apply.

Step 2: Sign using Adobe Acrobat Reader​

  1. Connect your agent.
  2. Open a PDF in Adobe Acrobat Reader.
  3. In the All Tools global bar, select View more.
  4. Click Use a certificate.
  5. Click Digitally Sign in the main menu. In the window click Ok.
  6. Use the mouse to drag and draw a rectangle area where you want your signature to appear.
  7. A window will appear. Select the certificate you want to use and then click Continue and Sign.
info

If you have a user PIN configures, you will be prompted to add it after you click Sign.

tip

You can also add a timestamp to your PDF using the Timestamp option under the Use a certificate option. You will only need a URL such as http://timestamp.digicert.com to configure it.

Step 3: Verification​

To verify that the process run smoothly, check the Events section in the admin console. You should be able to see the details of the use of the certificate.

warning

Bear in mind that depending on how you opened the PDF, the name of the signed file that appears on the event details may be misleading.