A 'brilliant' CalTech graduate-turned-hacker and cryptocurrency guru has been sentenced to five years in federal prison for helping North Korea evade US sanctions.

Virgil Griffith, 39, taught more than 100 people how to use blockchain technology to get around international restrictions at a crypto conference in Pyongyang three years ago. 

Many of the businesses and people he trained are thought to have worked for the North Korean government. Griffith, from Birmingham, Alabama, advised them how to gain independence from the international banking system. 

The CalTech graduate, who is the mastermind behind the Wikipedia tool WikiScanner, was sentenced to 63 months in prison and a $100,000 fine on Tuesday in Manhattan. 

He was described by his lawyer as a brilliant scientist who had peace as his only interest. Further details on how his antics were designed to encourage peace have yet to be shared. 

His sentencing on Tuesday comes after Griffith pleaded guilty last year to conspiring to violate the International Emergency Economic Powers Act. 

The law prohibits U.S. citizens from exporting goods, services or technology to sanctioned countries, including North Korea. 

America and the United Nations have issued sanctions against Kim Jong-un's government to deter its nuclear missile programs, first launched in 2018.  

Griffith said he regretted his participation in the 2019 conference and in light of the sanctions issued to Russia after the Kremlin invaded Ukraine, he 'was cured' from his North Korea obsession.