In everyday language, very different things are called a “digital signature.” Technically, there is a major difference between inserting an image of your handwritten signature, drawing a signature on a screen, and applying a cryptographic digital signature.
Which method is appropriate depends on the purpose, recipient, and any applicable legal requirements. This article explains the technical differences, not individual legal advice.
1. A scanned or inserted signature image
An image of your signature is exactly that: an image. It can show where a signature is intended, but the image itself does not cryptographically prove who inserted it or whether the document was changed later.
2. Electronic signature as a broad category
“Electronic signature” is commonly used as an umbrella term for electronic methods that express a person's approval or identity in connection with a document. Different systems can implement that idea in very different ways.
A drawn name on a touchscreen, a confirmed signing workflow, or other electronic mechanisms may all fall into this broad category. Their technical assurance depends on the specific method.
3. A digital signature in the cryptographic sense
A digital signature uses cryptography. In simplified terms, a mathematical proof is created that is tied to the signed document and a private key. That proof can be used to check whether the signed content has changed and which key was used to create the signature.
Certificate-based workflows are common in document signing. A certificate helps associate a public key with an identity or organization.
What a digital signature can add
- Integrity checking: was the signed content changed afterward?
- Technical association of the signature with a particular key.
- Depending on the certificate and trust chain, additional identity information.
The legal effect of any of these properties depends on the specific signing method and the applicable legal framework.
A visible signature and a cryptographic signature can appear together
A digitally signed PDF can also show a visible signature appearance such as a name, date, or handwritten image. That visible appearance is not the cryptographic proof itself.
What should you clarify before signing?
- Does the recipient require a specific type of signature?
- Does identity need to be verified to a particular standard?
- Should later document changes be detectable?
- Is a simple visible approval sufficient for the workflow?
- Which software or platform does the recipient expect?
Why PDF is common in signing workflows
PDF is well suited to distributing fixed document versions, so it is often used in signing workflows. That does not mean every PDF application supports the same signing features or that every visible signature has the same technical status.
Where Priviot fits
If you need to read or edit PDFs locally, you can use Priviot PDF. For cryptographic signatures and certificate workflows, always check the currently documented capabilities of the specific tool you plan to use; PDF applications differ significantly here.
Conclusion
A signature image is a visible graphic, an electronic signature is a broad process category, and a digital signature uses cryptography to support integrity checks and key attribution. What matters is not how similar the results look, but which process your use case actually requires.