Bitcoin’s soaring price may be aiding North Korea. In recent months, experts say the Hermit Kingdom has aggressively mined bitcoin, demanded it as a ransom payment and outright stole it from other exchanges. North Korean hackers targeted four bitcoin exchanges in South Korea this past summer, sending malicious emails to employees in an attempt to gain access. North Korea has repeatedly denied involvement in international hacking attacks. But it has made no secret of its interest in bitcoin and other cryptocurrencies. Last month, the Pyongyang University of Science and Technology touted a lecture from a bitcoin expert who came to North Korea to teach students about the technology behind the digital currency.