The difference between digital signature and digital certificates

There is some confusion surrounding digital signatures and digital certificates as they are often thought to be synonymous. While the two concepts are related, they are not the same. Here we explain the difference between a digital signature and a digital certificate.

What is a digital certificate?

The main difference between a digital certificate and a digital signature is that the former is a certification or electronic document issued by a Certification Authority (like the FNMT in Spain) that links a person with a public key and confirms his or her identity. This allows you to carry out certain processes and procedures online, including signing documents electronically.

You can find out how to obtain a digital certificate here.

There are different types of digital certificates, like a digital certificate for a natural person or the digital certificate of a legal entity. You can sign documents electronically with a digital certificate, which grants full validity to the digital signature. In some cases, you can obtain an electronic certificate online, but that is not common. Most of the time you have to physically present yourself at the certifying entity to verify your identity. 

The certificate can be installed in your browser or used through a qualified electronic signature creation device such as a:

  • Cryptographic card (like the electronic DNI, the Spanish national identity card)
  • Cryptographic USB
  • HSMs, which are cryptographic servers

If you have a qualified certificate issued by a Certification Authority when using the aforementioned types of devices, you can sign with a qualified electronic signature. This digital signature type is one of several outlined in the eIDAS Regulation and offers the highest degree of legal and security guarantees. 

What is a digital signature?

A digital signature is a cryptographic mechanism that, applied to an electronic document, allows the receiver to:

  • Clearly identify the signatory, and
  • Guarantee the integrity of the signed document (ensuring that it is original and has not been manipulated or altered since its signing). 

With a digital certificate, you can sign using a digital signature over the internet. However, you do not need a digital certificate generated by a Certification Authority to be able to securely sign documents electronically that hold legal validity.     

There are other tools that allow you to sign documents securely and legally. At Docuten, we offer different types of valid digital signature solutions that are adapted to the needs of your company so that you can get all your documentation signed electronically.

For example, with Docuten you can sign documents with a digital certificate. Our service lets you sign electronically with a digital certificate in two ways: with a certificate that you have hosted on your computer (an on-premise signature), or a certificate in the cloud (a centralised signature that lets you sign from anywhere).

Other types of digital signature

There are additional options that do not require a digital certificate, but hold the same legal validity, like the advanced signature.

Docuten offers two types of advanced electronic signature: the biometric signature and signature with OTP.

  • The biometric signature is often used for signing labor documentation in stores or offices by signing on a touch device, such as a tablet or smartphone. It is useful for signing employee training documents as well.
  • Alternatively, signing with an OTP (one-time password) is practical for multiple use cases, like signing contracts with clients remotely. This type of digital signature enables companies to continue working remotely, and has been especially useful during the pandemic when mobility restrictions were put in place.
digital signature and digital certificate

We help you find the right solution

Although related, the differences between digital certificates and digital signatures are clear: the former is a tool that enables the execution of the latter (i.e. the electronic signature with a digital certificate).

At Docuten, we aim to offer our clients their ideal solution in terms of security and legality. If you want more information about our digital signature services or to learn more about the legality of the qualified electronic signature, our signature in the cloud or the electronic signature with a digital certificate, don’t hesitate to contact us. We would be delighted to help your company go paperless.

Interested in how an electronic signature is legally binding? Check out our post on eIDAS

Mónica Fustes
Mónica Fustes