A cryptocurrency expert was sentenced Tuesday to more than five years in federal prison for helping North Korea evade US sanctions.

Virgil Griffith, 39, pleaded guilty last year to conspiracy, admitting he presented at a cryptocurrency conference in Pyongyang in 2019 even after the US government denied his request to travel there.

A well-known hacker, Griffith also developed “cryptocurrency infrastructure and equipment inside North Korea,” prosecutors wrote in court papers. At the 2019 conference, he advised more than 100 people — including several who appeared to work for the North Korean government — on how to use cryptocurrency to evade sanctions and achieve independence from the global banking system.

The US and the UN Security Council have imposed increasingly tight sanctions on North Korea in recent years to try to rein in its nuclear and ballistic missile programs. The US government amended sanctions against North Korea in 2018 to prohibit “a US person, wherever located” from exporting technology to North Korea.

Prosecutors said Griffith acknowledged his presentation amounted to a transfer of technical knowledge to conference attendees.

“Griffith is an American citizen who chose to evade the sanctions of his own country to provide services to a hostile foreign power,” prosecutors wrote. “He did so knowing that power — North Korea — was guilty of atrocities against its own people and has made threats against the United States citing its nuclear capabilities.”

Defense attorney Brian Klein described Griffith as a “brilliant Caltech-trained scientist who developed a curiosity bordering on obsession” with North Korea. “He viewed himself — albeit arrogantly and naively — as acting in the interest of peace,” Klein said. “He loves his country and never set out to do any harm.”

Klein added that he was disappointed with the 63-month prison sentence but “pleased the judge acknowledged Virgil’s commitment to moving forward with his life productively, and that he is a talented person who has a lot to contribute.”

A self-described “disruptive technologist,” Griffith became something of a tech-world enfant terrible in the early 2000s. In 2007, he created WikiScanner, a tool that aimed to unmask people who anonymously edited entries in Wikipedia, the crowdsourced online encyclopedia.

WikiScanner essentially could determine the business, institutions or government agencies that owned the computers from which some edits were made. It quickly identified businesses that had sabotaged competitors’ entries and government agencies that had rewritten history, among other findings.

“I am quite pleased to see the mainstream media enjoying the public-relations disaster fireworks as I am,” Griffith told The Associated Press in 2007.

Klein previously said Griffith cooperated with the FBI and “helped educate law enforcement” about the so-called dark web, a network of encrypted internet sites that allow users to remain anonymous.