Digital Signatures perform the same function as actual signatures do, to approve a document. However, advanced security and user information gives digital signatures an advantage over the traditional pen-on-paper scribble. You also do not need to print the document in order to sign and authorize it.
With your digital signature it’s easy to prevent any accidental, unauthorized, or illegal changes to a PDF document. Any modifications to a signed document invalidates the signature immediately and it cannot be restored unless the original user signs the document again. See Signing a PDF.
The first signature in a document is called the author signature. When you add the first signature to a document, you have the option to certify the document. Certifying a document lets you validate its contents and specify the types of changes allowed for the document to remain certified. Changes to the document are detected in the Signature tab. Subsequent signatures to the document are called ordinary signatures.
You must select a digital ID to sign a document. The digital ID contains the signature information that you can share with other users in a certificate. You can create a self-signed digital ID, or obtain a digital ID from a third-party provider. Using certificates, other users can validate your signature and vice versa.
- Signing a PDF
- Certifying a PDF
- Timestamping a Signature
- Using the Sing/Certify Panel
- Verifying a Signature
- Using the Signature Panel