The main benefit of a central bank digital currency would be increased efficiency and it would provide a more inclusive payment system, Federal Reserve Chairman Jerome Powell said in a discussion hosted by the Bank of International Settlement.However, there's also significant risk. "There's cyber risk as well as money laundering and terrorist financing" risks, he said during the online effect.Echoing earlier comments he has made, Powell said the central bank is in no rush to issue a CBDC and isn't yet in "decision mode" on the matter.Since the U.S. dollar is the world's reserve currency, "a CBDC would have potentially large implications here and around the world," he said.Also, the Fed doesn't want to compete with banks for funding, he added.