How do I delete all existing digital signatures in Adobe Acrobat?

Hi Roger,

I'm a little confused as to your question. Let's start with some background just so we're on the same page.

A "digital ID" is the equivalent of a pen in the physical world. It's used to create a "digital signature" just like a pen is used to create a "wet ink" signature. A "digital signature" is the equivalent of a "wet ink" signature on a piece of paper. So, just like you use a pen to create a wet ink signature on a piece of paper, you use a digital ID to create a digital signature on an electronic document. Also, just like in the physical world you can use a pen to sign anything (e.g. a cast on broken arm, an art canvas, a wall, etc.) you can digitally sign any electronic blob of data (e.g. a PDF file, an e-mail, a Word Doc). Of course we're concentrating on a PDF file here so we'll keep to Acrobat and Reader.

The digital ID contains three separate pieces of information; a private key, a corresponding public key, and the public-key certificate information (the text that you see like the subject name, the issuer name, the validity dates, etc.). Because the digital ID contains the private key it has to be protected to prevent unauthorized use (aka "key compromise"). The digital ID can be saved in one of several places. It can reside in a password protected file, it can be on a PIN protected smart card or token, it can be on a special server, or the operation system (OS) can manage it. For the OS it's either Mac Keychain Access, or the Windows Certificate Store. On Windows, don't think of "store" as a place to buy things, but rather just a storage location. If the OS is managing the digital ID then the log-in to your account is the only authorization required for access to the digital ID so you don't see subsequent password requests.

When it comes time to digitally sign a PDF file you are go to need access to your digital ID. When the Sign Document dialog is displayed (and here's where I think your question lies) whether the Password edit field (the place you type in your password) is displayed or not depends on where the digital ID resides. If the digital ID is in a file then you see the Password edit field, but if the digital ID is being managed by the OS then you don't. As I noted above, if you were able to log into your account on the computer the OS takes that as all the authorization required to gain access to your digital ID and you don't get a subsequent request for a password. The question you have to ask is "where does my digital ID reside"? To find out do the following:

• Open the Tools panel on the right side of Acrobat
• Expand the Sign & Certify pane
• Click on the More Sign & Certify > Security Settings menu item
• Select Digital IDs at the top of the tree view on the left side of the Security Settings dialog
• On the upper right list box there is a column labeled "Storage Mechanism".

If the "Storage Mechanism" is either "Mac Keychain Store", or "Windows Certificate Store" then you won't see the Password edit field on the Sign Document dialog.

Does this answer your question?

Steve