CREDIT: AP Photo/Rick Bowmer Digital currencies like Bitcoin could give impoverished Native American tribes an economic boost by giving them an alternative to the United States dollar. That’s what Native American activist Payu Harris is hoping will happen once MazaCoin takes off. Even as Bitcoin’s global system is rocked with the meltdown of its largest exchange, Harris introduced a Bitcoin spin-off, dubbed MazaCoin, at a digital currency conference in New York on Monday.