DALLAS (AP) — Pro Football Hall of Famer Emmitt Smith has signed hundreds of helmets, jerseys and scraps of paper. But with each autograph he knows is his, the former Dallas Cowboys running back worries about the fakes that may one day be passed on to unsuspecting fans.

The Dallas Morning News reports the 48-year-old football star has created a company that makes those fakes easier to spot. Now when Smith signs his name, he uses a smartphone to scan a chip on the item or embedded into it. Through a mobile app, he can register the item so later anyone who buys it can prove it's authentic.

He wo...