How to sign a PDF digitally in Ubuntu Operating System.

++Updating this old thread,

A  PDF that is shared with other recipients via Adobe Sign can be filled and signed from any computing device, regardless of operating system, using any supported web browser (there is no need to have Adobe Reader or a paid subscription of Adobe Acrobat Pro).

• https://helpx.adobe.com/acrobat/using/send-for-signature.html

NOTE#1

The ability on how to employ a certificate-based digital signature on a PDF document varies among different operating systems.

Specifically using smart cards. The references below may be helpful:

• https://askubuntu.com/questions/285543/how-do-i-install-and-configure-a-security-card-cac-reader-for-ubuntu-13-04

• https://help.ubuntu.com/community/CommonAccessCard

• https://askubuntu.com/questions/1364460/i-cannot-get-my-scr3310-smart-card-reader-to-work-in-ubuntu-20-04-2-despite-ins

• https://askubuntu.com/questions/147379/how-do-i-digitally-sign-a-pdf-with-a-s-mime-certificate

NOTE#2

You may also use Adobe Online Services via web browser (a subscription plan to Adobe Acrobat Pro DC is required) to Fill and Sign PDFs electronically using any supported web browser regardless of operating system:

• https://www.adobe.com/acrobat/online/sign-pdf.html

Hello Gail Agmednet,

The support of Reader and the digital sign and the feature are  not available in Ubuntu. You may refer to the following KB doc which discusses the similar issue Where to get Acrobat Reader for Ubuntu?  https://forums.adobe.com/thread/1905725

I have also shared more information via private message, please check your email inbox.

Hope this helps.

Regards,

Anand Sri.