Policy in place for digitally signing ‘official’ e-mails Published Feb. 12, 2009 By Brandice J. Armstrong Tinker Public Affairs TINKER AIR FORCE BASE, Okla., -- There is a new Air Force Materiel Command policy in place, which officials said, will affect all Tinker network users. According the policy, e-mails that contain official Air Force business including messages that provide direction, commitment and official correspondence require a digital signature. Installation network users will soon have a tool that enforces signatures on e-mails that have attachments, Web links and shared-drive information. "Signing provides non-repudiation," said Mark Van Duker, 72nd Communications Squadron Network Control Center chief, "[which means] a sender cannot deny that he sent it, because a CAC card and pin were needed. The persons who send messages are who they say they are and they intended to send them." Without digitally signing an e-mail, a message can be forged. Mr. Van Duker said with a little know-how, a sender can make a message appear as though it were sent from President Barack Obama or former President George W. Bush. Persons replying or forwarding an e-mail with a digital signature must also digitally sign their message. If they cannot, the message should not be replied to or forwarded, according to the policy. Digitally signing an e-mail is a matter of clicking an icon in a new message's task bar. Found in the upper right corner, the icon resembles a yellow envelope with an award-medal's red ribbon off to its left side. Mr. Van Duker said remembering to click the digital signature icon for specific e-mails may be the most challenging aspect of the new regulation. For more information, questions or comments, call the Help Desk at 734-4357 or e-mail help@tinker.af.mil.