Skip to content

How to make a digital signature on a legal Mac with a digital certificate

In a society that is moving towards the digitalization of most of its procedures, it is important to take into account the need to know how to perform the digital signature. There are many programs that we can find official to carry out this procedure, but we must always go to official sources to download them.

Electronic ID or digital certificate

It is important to note that an official digital signature requires a digital certificate or an electronic ID card. There are many applications that allow us to sign a digital document simply by taking a photograph of our signature on paper. But this is not valid to carry out official procedures or to sign contracts. In these cases you should always use an official certificate, which can guarantee that the signatory is who he says he is. This can only be achieved through digital certificates .

How to make a digital signature on a legal Mac with a digital certificateHow to make a digital signature on a legal Mac with a digital certificate

In Spain, with the electronic ID we always carry a certificate with us. The only drawback is that you need a compatible reader so that you can read the DNI chip and load this certificate. It is also necessary to know the password of the DNI, because to prevent anyone from accessing this valuable information the certificates are password protected. To get it you simply have to go to a police station where they will tell you how to renew it. There are many readers on the market that are compatible with macOS, and the truth is that they are not worth much money. If you are a person who needs to sign official documents often, it is essential to have one. In order to use this reader, it is essential to install the drivers that you will find on the National Police website .

Although it is not essential to have the certificate of the DNI, as there are many other electronic certificates issued by public bodies. For example, the Mint issues this type of certificate, which is also valid.

AutoSign, the application for digital signature

Once you have your certificate, you must download the application used to digitally sign documents. This is called AutoSignature and can be downloaded comfortably from the website of the Ministry of Economic Affairs and Digital Transformation in a secure way. We always recommend using official applications, as using certificates in untrustworthy applications is not the best way to go.

Download AutoSignature

Once the software is downloaded and installed, connect your electronic ID to your Mac if you need it. When you start, you’ll see that you have a choice between using an electronic ID or a certificate. You can choose the one you want and opt for the most convenient size with the ID or upload a certificate manually. In the case of the DNI, you will be asked for the authentication key.

When you have uploaded the certificate, you must choose the files you want to sign by dragging them or selecting them with the Finder. Once uploaded, you will be asked if you want to include in the document itself a visual proof that it is signed by you. You can mark it if you want and choose in the next window the place where you want your name to appear with the date or the data you see. It is also possible to add an image of your signature if you scan it to make it more integrated.

But what’s really interesting is that when you sign the document, it generates another one that you can keep wherever you want. This may have the visual mark that you have signed it, but the authentication will be visible if you right-click on it and click on ‘Get information’. Here you will see clearly that it is signed with a fully valid certificate and program, so that it can have legal validity.

As you can see, it is very easy to perform the digital signature being the most tedious thing to manage the digital certificate. But once this step has been overcome, the signature becomes tremendously comfortable.