Korean yen
The Korean yen was the currency of Korea between 1910 and 1945. It was equivalent to the Japanese yen and consisted of Japanese currency and banknotes issued specifically for Korea. The yen was subdivided into 100 sen. It replaced the Korean won at par and was replaced by the South Korean won and the North Korean won at par.
Superdollar
It has been confirmed that North Korea has passed off superdollars (Korean: "kattalio") in various countries. The counterfeit bills also circulate both within North Korea and around its border with China. There is, however, some doubt about the reliability of North Korean defectors' claims, on which the United States partially bases its accusations, along with South Korean intelligence sources.