Contact Us

What is a digital signature?

Nerilda Meda
The cover image for blog titled What is a digital signature?

What is a digital signature? Why digital signatures are different from electronic signatures?

Electronic and digital signatures are increasingly common as consumerization grows and new technologies creep into every aspect of our lives. But what exactly is a digital signature? And how is it different from an electronic signature?

Today, there are four common types of signatures. Three of these are classed as electronic signatures, and two of these electronic signatures are classed as digital signatures:

1. Wet ink signatures

The old-fashioned approach of a pen, paper and wet ink. If you’re signing something by hand, this is deemed a ‘wet ink signature’.

2. Simple electronic signatures

In most cases, a simple electronic signature is an image of a signature (a .jpg or .png file) inserted into a document, a click of a mouse indicating a ‘signature’ agreement, or the use of fingers on a handheld device to trace a ‘handwritten’ signature. Even just typing your name at the end of an email could be classed as an electronic signature.

3. Advanced electronic signatures

Advanced electronic signatures are more secure than simple electronic signatures. They are generally created with public-key infrastructure (PKI) technology. They offer more control because any changes to the document after the signature are detectable. They are also linked to and capable of identifying the signatory.

4. Qualified electronic signatures

Qualified electronic signatures are built on the same principles as advanced electronic signatures — with two crucial additions:

· They are created by a qualified signature creation device

· They are based on a qualified certificate for electronic signatures

For more details on these requirements, see eIDAS Annex II.

Only advanced electronic signatures and qualified electronic signatures are digital signatures, because they are the only signatures that rely on PKI technology. This means they guarantee non-repudiation and identity authentication. Qualified electronic signatures, in particular, often have a legal status similar or equal to wet ink signatures.

To find out more about digital signature and trusted digital identities, visit

What is a digital signature? was originally published in KOBIL on Medium, where people are continuing the conversation by highlighting and responding to this story.