Digital Signing and Encrypting PDF – Acrobat Reader DC   Digital signatures identify/authenticate you as the document signer and allow document recipients to verify that no one has modified the contents of the document since you signed it. Signing, Encrypting and reading will vary depending on the applications that are involved. A Digital ID certificate is required to create a digital signature. The most secure Digital ID are issued by a trusted Certificate Authority. Some of these Digital ID’s are on tokens and other are files that are imported into trust stores on your system or application. Note:  Adobe Acrobat Reader DC is used for signing pdf files that application can be downloaded by visiting the Adobe Website  here. Note:  If you cannot download this application due to firewall permissions or It has not been cleared within your organization  then you will need to do the needful and contact your companies IT team. To sign a pdf document perform the following: Step 1