This photo released by North Korea's official Korean Central News Agency shows Kim Jong Un visiting the People's Theater this month to mark the 70th anniversary of the founding of the State Merited Chorus in Pyongyang. (AFP/Getty Images)

As ordinary North Koreans have found ways to get information the state denies them — soppy South Korean dramas and peppy pop songs, novels, news from the outside world — so too has the Kim regime found news ways to crack down on them, according to a new report released Wednesday.

The regime has developed sophisticated new tools to check just what its citizens are up to, according to Compromising Connectivity, a new report from Intermedia, a Washington-based research group.

The report underlines the challenges in getting information into the most tightly controlled country on the planet — and the challenges that North Korea watchers as diverse as the U.S. Congress and small defector-led groups face in trying to penetrate it.

“In a lot of ways, the expansion of information is continuing,” said Nat Kretchun, the lead author of the report, which draws on interviews with 34 recent defectors from North Korea. “It’s just that we also see a lot of signs that the North Korean government is gearing up to combat it.”

Kim Jong Un, his father and his grandfather have kept a tight grip on the North Korean populace for more than seven decades by denying citizens access to information. State television, radio and newspapers laud the work of the Kim family, telling North Koreans how lucky they are to live in such a strong and happy country.

But thanks to dramas smuggled in on USB sticks and illicit shortwave radio broadcasts from the outside, an increasing number of North Koreans have realized that their brethren in the South enjoy unimaginable levels of wealth and freedom. Being caught with such banned media can result in harsh penalties, including imprisonment.

At the same time, the introduction of cellphones — albeit for domestic calls only, and without Internet access — is allowing people around the country to share information much more freely internally.

High-profile defectors such as Thae Yong-ho, who served as a North Korean diplomat in Europe for almost 20 years, have described the transformative effect of outside information and have urged governments and NGOs to flood North Korea with it.

While imposing new sanctions on North Korea last year, Congress allocated $50 million over the next five years for radio programming and the promotion of freedom of information inside North Korea.

But the real picture is more complicated, the Intermedia report says.

“They’re clearly trying to innovate their way out of the breakdown of the security apparatus rather than going back to Kim Il Sung times,” Kretchun said, referring to the founding president of the totalitarian state. North Korea’s security apparatus began crumbling in the 1990s, after a devastating famine that gave the regime no choice but to tolerate markets — which then became a venue for sharing information.

(Jason Aldag,Anna Fifield/The Washington Post)

“They now have a vision of a more sophisticated but no less controlled media environment,” he said.

Take cellphones. North Koreans are now allowed such devices — including a re-branded Chinese Android-based smartphone called Arirang.

As recently as 2013, North Koreans could use these to share files — including songs and text — through Bluetooth or micro-storage SD cards. But a mandatory software update rolled out in 2013 included a program called “TraceViewer” that would collect browsing history and take periodic screenshots of activity — which the user could not delete. That means the security services can see exactly what the user has been up to, long after they have removed any SD card.

The update also included a “signature system” that would prevent a device from opening any files that don’t bear a North Korean state signature — and, in fact, automatically deletes them.

“Even with the network restrictions that were applied at the beginning, cellphones could have been a game-changing device in North Korea,” Kretchun said. But the system update stops that from happening.

“North Korea has a unique advantage in that it can dictate what devices their people have,” he said. He added that the state has made it very difficult for citizens to undermine their technology. “They put a lot of work into making sure you have to be quite technologically sophisticated to do the equivalent of jailbreaking these phones.”

Access to outside networks has also been curtailed. Residents on the border with China have been able to get signals on Chinese phones, but the regime appears to have cracked down on this, using jammers and signal detectors.

“Once, I went into a house and made a call to China and inspectors came within 30 seconds,” said a 59-year-old man who used to work for a trading company near the Chinese city of Dandong. “There are inspectors going around with an eavesdropping device to control calls to China,” he told the report’s authors.

But North Koreans are still able to watch movies and dramas at home relatively easily.

Previously, they watched foreign movies and soap operas on DVDs smuggled into the country, but in recent years they have developed a preference for USB sticks and SD cards, which are easier to hide. They plug the USBs or SD cards into their DVD players — which are permitted, although only to watch North Korean propaganda — and make sure to have a DVD in the drive in case of a spot inspection.

Small portable DVD players called “notels” also are used for watching foreign dramas.

Using small storage devices not only allows North Koreans to hide them easily during raids but also enables them to share media with each other. All but one of the North Korean defectors Intermedia interviewed said they had shared content with others.

Despite the challenges, Kretchun said there was reason to keep trying to penetrate the North Korean regime’s information blockade. “Right now, all the arrows continue to point up. People are still certainly watching foreign dramas and listening to the radio,” he said.