The Technical Stuff
Baily Garner have introduced digitally signed pdf documents using a 1024bit encryption public key infrastructure (PKI) certificate issued to Baily Garner from VeriSign. The certificates are held on a Class 2 crypto device, with access being controlled via a microsoft active directory authentication using a Strong Password Policy. What this means is that you have the peace of mind to know that signer’s digital identity is legitimate.
The ‘signature’ will appear on each document in a similar looking format and will include the name of the authoriser, the date and time the document was signed and a web link to this page to help explain digital signatures, see example
This gives you the assurance that the information has not been altered since it was authorised, as any modification made to the document after signing will invalidate the signature, and acrobat reader will allow you to see what was actually signed (the original document).
For more information see http://www.adobe.com/security/digsig.html