Like a handwritten signature, a digital
signature is uniquely yours. Acrobat includes features to keep your
digital signature secure. Unlike traditional signatures, digital
signatures can contain additional information, such as the date
and time of signature and the reason for signing. Just as you developed
your own signature style early in life, you can add your own flair
to your signature appearance, as well.
Obtain a digital
ID.
If you don’t already have a digital ID, create a self-signed
digital ID in Acrobat. A self-signed digital ID includes an encrypted
private key for signing or decrypting documents. It also includes
a public key in a certificate used to validate signatures and encrypt
documents.
To create a self-signed digital ID, choose Advanced
> Security Settings. Select Digital IDs on the left, and then
click the Add ID button in the toolbar. Select A New Digital ID
I Want To Create Now, and continue through the wizard.
Type
the personal information for your digital ID, including your name.
When you certify or sign a document, the name appears in the Signatures
panel and in the signature field. Name your digital ID and create
a password for it that contains at least six characters, with no
punctuation marks or special characters. Click Finish. Make a backup
copy of your digital ID file, in case the original is lost or damaged.
Create an appearance for your digital signature.
Your
digital signature can be simple or complex. It can look like a handwritten signature
or a typed name. It can contain a company logo, include the date and
time you signed, and state a reason for signing. You can create
multiple signature appearances for different uses; select one each
time you sign a document. If you want to include an image of your
signature, scan your signature and save it as a PDF.
To create
an appearance, choose Edit > Preferences (Windows) or Acrobat
> Preferences (Mac OS). Select Security on the left, and then
click New in the Digital Signatures section. Give the signature
appearance a short, descriptive title that you’ll recognize when
you’re signing a document. Select options, including whether you
want to include an imported graphic, such as a scanned signature.
As you make changes, your edited signature appears in the preview
window. Click OK.
If
you selected Reason, click Advanced Preferences, and, in the Creation
pane, select Show Reasons When Signing. If you selected Location,
select Show Location And Contact Information When Signing.
Review the document carefully.
Before you sign any
document, physically or electronically, make sure that you know
what you are signing and where all the signature fields are. Because dynamic
content might alter the appearance of the PDF and mislead you, view the
document in Preview Document mode before signing. To use Preview Document
mode, open the Preferences dialog box and select Security on the left;
then, select View Documents In Preview Document Mode When Signing.
Check
each page of a document for signature fields. You may need to sign
a document in more than one place. Each signature field is unique,
so your signature won’t automatically be copied from one field to
the other signature fields in the document.
Sign the PDF.
To sign the document, click the signature
field. If no signature field exists, choose Sign > Place Signature
from the Tasks toolbar and draw a signature field on the page.
If
you’ve set Acrobat to display documents in Preview Document mode
before signing, a document message bar reports whether any dynamic
content exists in the document. When you’ve reviewed the document,
click Sign Document in the document message bar to proceed.
In
the Sign Document dialog box, select an appearance, and then add
any information it requires, such as the location or the reason
for signing. Enter a password if your digital ID requires it. Click
Sign. Give the document a new name so that you can change the original
PDF without invalidating the signature, and click Save.
When
you apply a digital signature, Acrobat embeds an encrypted message digest
in the PDF. Acrobat also embeds the details from your certificate
and a version of the document at the time it was signed.
Distribute your certificate.
To verify your digital
ID, others who view your document must have the public certificate
from your digital ID. To send your certificate, choose Advanced
> Security Settings, and select Digital IDs on the left. Expand
the list, select the digital ID you want to share, and click Export.
Follow the onscreen instructions to email your certificate as an
FDF file to someone or to save the certificate as a different file
type.
