Korean currency
In 1902, won was introduced as the official currency unit replacing yang at 1 won = 5 yang. The bank of Korea was established 1909 but soon after in 1910, Imperial Japan annexed Korean Empire. Under Colonial rule, the country was made to use the currency unit "yen" in the name of Korean yen, which took over the Korean won at par. After the division of Korea, the state of South Korea was established and recognized in 1948, and won was again made the official currency of the new state. "jeon" was made the subunit of the currency that divided it into 100 equal parts. Bank of Joseon issued the currency for independent South Korea for the first time that too in banknotes only.
North Korea's illicit activities
Counterfeiting currency is alleged to have begun in the 1970s under Kim Jong-il's direction; however, the notes produced at the time were not of high quality. Since then, and within the jurisdiction of Room 39, the North Korean government has counterfeited $50 and $100 United States banknotes using increasingly sophisticated techniques. In 1994, authorities in Hong Kong and Macao apprehended five North Korean diplomats and trade-mission members carrying around $430,000 in bills that turned out to be "superdollar" (also called "supernote") counterfeits. There have been two primary reasons for counterfeiting: the first is to wage economic warfare against the United States, and secondly, to help ease North Korea's domestic economic problems. According to a report by Dr. Balbina Hwang of American University, North Korea circulated $100 million in counterfeit currency in 2001. The revenues from this are estimated at between $15 million and $25 million annually. In 2013, the United States released its newly redesigned 100 dollar bill. The primary purpose of the redesign was to fight against counterfeiting and prevent the recurrence of the "supernotes" which were produced by North Korea.