Understanding digital certificates: The key to secure document signing

Karina Schulz Wharwood,  Kategorien:

We live in a digital world. This not only means our documents can be shared more easily but also more securely. This is where digital certificates step in. Think of a digital certificate is as a digital ID or passport, similarly to the way our personal IDs verify who we are, this is what they do for machines. Why do we need a form of electronic ID when it comes to document safety? Read on to find out.

Understanding digital certificates

Digital certificates are important to establish trust and security when it comes to online communications. By having one, you can prove that the PDF and signatures come from a legitimate source.  

To ensure that a certificate used for a signature is valid, it must be issued by a trusted certificate authority. They validate the identity of the applicant before providing the one. This is another way the recipients can check that the data really comes from you and not a potential scammer.

To get a digital certificate in your country, select an established certificate authority or recognized entity in your country that issues them.

Digital certificates act as an ID card for machines

Digital certificates help authenticate the sender

Why digital certificates matter

Let’s say, for example, that you receive a signed file (PDF, program, or printer driver) or install a program. How can you be sure that it is from a legitimate source? By seeing that a publisher has signed a PDF or program with their certificate, you’ll immediately know that it has been authenticated and that the identity of the sender has been validated by a trusted source.

There are three key reasons why organizations use digital certificates:

  • Authentication

A certificate authenticates the sender's identity. A signed PDF, for example, can be verified to be from the organization that signed it.

  • Security

Digital certificates ensure that the content of a document or file has not been changed since it was signed. If someone tries to alter the file, a check method shows that the document was changed by someone.

  • Trust
    Certificates show that a recognized authority has validated the organization’s identity. This gives recipients confidence when exchanging sensitive information.

When a digital certificate expires

Every digital certificate comes with a validity period set by the certificate authority that issued it. Just like a passport or driver’s license, it has a start date and an expiration date. But why do certificates expire?

  • Security: Encryption standards evolve, and certificates must be renewed to keep data protection strong.
  • Trust: Expiration ensures organizations stay accountable by updating and renewing their identities with the issuing authority.

How certificate expiration affects documents and signatures

When a certificate expires, it no longer works for new documents that need signing. To authenticate those files, you will need a new certificate. However, any PDF or file that was signed while the certificate was valid will still carry valid proof of authenticity.

Think of it this way: if you use your passport or ID to verify your identity when buying a property, the verification remains valid even if the proof of identiy expires later. Similarly, a contract signed with a valid digital certificate remains secure and trusted even after the certificate itself has expired.

Renewals and secure workflows

Organizations often prefer to renew their certificates before expiration. Modern systems tend to handle this smoothly. If your license or certificate has been renewed through the issuing authority, your workflows remain secure without disruption. You don’t need to restore old certificates. Renewed credentials keep your systems authenticated and running as intended.

Use case:

Imagine an organization wants to send legally binding contracts to one of their clients. By using PDFCreator with digital certificates:

  • The receiver proves the authenticity of the sender
    Clients know the contract truly comes from the organization. They can trust the document because the organization’s identity has been verified.
  • The document remains secure
    If anyone attempts to modify it, then a check will immediately show that the document has been changed post signature.
  • The workflow gains efficiency
    There is no need for manual checks or physical signatures. The document still meets compliance requirements.

This same secure workflow applies to invoices, HR documents, government forms, or any sensitive file that require security and authentication.

Managing digital certificates with PDFCreator and PDF Architect 

Both PDFCreator and PDF Architect support the upload of digital certificates, which are stored securely within your system and tied to your identity. However, there are different types of signature types to choose from, and choosing the right method will depend on the purpose of the document.

  1. Digital signature
    With a digital signature, you select a valid certificate and apply it to the document via either PDFCreator or PDF Architect. This method is best used for legal or professional contracts as it provides greater assurance.
     
  2. eSign
    This stands for email-based signing. It is commonly used for internal approvals within organizations and doesn’t require a digital certificate. Rather than being a personal signature, it authenticates the signer via their email address.
     
  3. Fill & Sign
    This method allows you to upload an image of your handwritten signature. It is a quick and convenient way to sign informal documents that don’t require proof of authenticity. Keep in mind that it is not a legally binding method for signing.

Practical example: Avanquest pdfforge is signing the PDFCreator printer driver. If the certificate used for this signing process is no longer valid, the printer driver remains valid and does not need to be signed again.

Protecting your documents with certificates

PDFCreator can create digitally signed PDFs using a valid certificate but cannot verify or check certificates. For this, you would need to use a PDF reader like PDF Architect. By using PDF Architect, you can both create and verify if a certificate is attached, and if any changes have been made after the signature.

Frequently asked questions about digital certificates and signatures

A digital certificate is trustworthy if it is issued by a recognized certificate authority, shows as valid in your system, and confirms the identity of the sender.

When a certificate expires, it cannot create new digital signatures. However, all documents and data signed during its valid period remain secure and trusted.

You can check the certificate details to confirm the authority that issued it, the authentication period, and whether the digital signature is still valid.

Any organization handling sensitive data or requiring secure authentication benefits from digital certificates. They provide trusted signatures and proof of identity in business workflows.

A digital certificate is the trusted ID issued by an authority. A digital signature is the secure mark created with that certificate to protect data and confirm authenticity.

Certificates are issued by trusted certificate authorities or through local providers that follow security standards.

Private users don’t always need a certificate, but it can add secure authentication and trusted digital signatures when signing contracts, wills, or sensitive personal data.

Digital signatures rely on two keys. The public key is shared openly and can be used to verify that it was signed by the owner of the private key and that document has not been altered. Meanwhile, the private key is used to create digital signatures and is kept secret by the signer. They work together to keep data secure and trusted.

Secure document signing doesn’t have to be complicated.

Take full control of your digital documents with PDF Architect. From editing and converting to secure electronic signing, PDF Architect gives you the flexibility to manage every stage of your workflow.

 Protect sensitive information with advanced security features, collaborate seamlessly, and ensure compliance with ease.

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