SEOUL, South Korea | North Korea’s recent “filth balloon” offensive against South Korea highlighted the depth of the paranoia in the regime of Kim Jong Un about information infiltration.

Last week, Pyongyang released more than 1,000 balloons carrying garbage and manure over the DMZ in retaliation after balloons launched by anti-regime activists in the South. Balloon flights from the South are a rare example of information warfare — waged by private groups, not the government in Seoul — aimed at Mr. Kim and his elites.

Pyongyang has maintained a near-total control over information domestically via a triple-tier system of human surveillance. But now it appears Mr. Kim’s regime is trying to buttress this with a high-tech, Chinese-style spyware system to keep unwanted messages out.

North Korea operates a localized intranet unconnected to the global internet. It has run its own cellular services since 2002, installed by the Egyptian telecommunications firm Orascom, which has reportedly been unable to collect on its contract due to foreign exchange controls.

But the North’s attempts to install digital surveillance networks so far have been hobbled by an inconsistent power supply, limited network capacities and lack of hardware, experts say. Digital networks and networked devices offer authoritarian states not restrained by privacy laws a wide range of methods to keep tabs on their own citizens.

“One of the things that is impossible to ignore in the last few years is how China has developed into a society that has used digital surveillance to monitor and control its citizens,” Martyn Williams, a senior fellow with the Stimson Center’s North Korea-focused media 38 North, told Seoul-based reporters. “So, it is natural to assume that North Korea would adopt the digital technologies that China is using.”

Mr. Williams’ team uses open-source intelligence, state media, trade show products, North Korean academic research, defector interviews and even Chinese social media to gauge the state of Pyongyang’s digital repression. The North’s cellular network boasts a new 4G service — detectable even in parts of northern South Korea. All indications are that cellular service is widely used.

“There is no reason to think they have a low cell phone penetration rate,” Mr. Williams said. “We have identified over 100 base stations — just the ones we have found via satellite imagery — and assumed [three-mile] coverage,” though mountainous areas of the country remain without service.

Despite its isolation and poverty, “North Korea has a really high level of aptitude when it comes to software engineering, but it does not have a large hardware industry,” Mr. Williams said. “All its smartphones come from Chinese companies, but the security software on them is all developed domestically.”

Devices exported to North Korea are manufactured by non-branded Chinese companies, rather than by major exporters who could face global sanctions. Ten separate North Korean companies sell imported phones to the public.

Expanding opportunities

There are expanding opportunities for the regime to monitor the population for suspect activities or opinions.

Pyongyang has introduced digital ID card, while QR payment codes have been synced with digital markets. Smartphones contain in-built screen-capture software, allowing authorities to scrutinize users’ viewing habits. Phones are locked for non-North Korean users: Engineers have failed to hack phones taken outside the country with USB sticks, Mr. Williams said.

Biometric techniques — fingerprint and facial recognition — date back to the 1990s. And a network of Chinese-made closed-circuit TV cameras, backed by local algorithms, is being rolled out nationwide, from farms to factories.

“North Korea has been devoting a lot of resources to facial recognition technology,” Mr. Williams said. “It can tell the state who is in a particular place at a particular time.”

On streets and highways, cameras monitor traffic. On the frontier with China, border guards can be watched by closed-circuit TV.

“This might go some way to explain why the northern border is so tightly closed,” Mr. Williams said. “It is not just additional security; security services themselves are being monitored … and have to watch what they are doing.”

Similarly, cameras positioned in classrooms over the last four years monitor teachers as well as students, he noted.

Six cameras on one state farm scrutinize not only work areas, but monuments celebrating the achievements of the regime. “It’s interesting that they seem to keep those under surveillance,” Mr. Williams said.

“Increased surveillance in North Korea is not necessarily against individual citizens but against all levels of society, to make sure they are doing the jobs they are meant to be doing,” he said.

Television is delivered to the home over internet protocol networks, offering new snooping opportunities. The state IPTV system carries Pyongyang’s four TV channels to rural areas that only have one.

“Netflix tracks what you watch, but in the North Korean context, you can find out what people do not watch,” Mr. Williams said. “That starts to become scary — if you decided to change channels when Kim’s speech came on.”

Still, North Korea’s digital surveillance systems are “nowhere near” China’s capabilities, Mr. Williams said, hampered by a lack of funds to upgrade its systems.

North Korea, “wants to emulate the Chinese police state, but will have trouble doing it because it lacks the foreign currency needed to purchase advanced systems,” said Geoffrey Cain, who heads NGO The Tech Integrity Project. “Most of the [state’s] technological capabilities rest with its skilled hackers, and that’s it.”

Another issue is power supply: “North Korea does not consistently have 24-hour electricity all over the country,” Mr. Williams said. “Digital surveillance and QR codes are useless if you don’t have electricity.”

Puny computing power is yet another limiting factor. Pyongyang currently lacks “a sophisticated data center and good networking back to the data center,” Mr. Williams said. Most of North Korea runs technically limited 3G services which are “really slow, these days,” he said.

Still, upgrades are underway. Surveillance cameras may be able to run off solar panels, and the new 4G service enables nationwide networking of television footage to a national data center.

A three-tiered surveillance state

Even without the upgrades, the three-tiered surveillance system now in place is formidable, said Kim Kwan-jin, a North Korean defector and senior analyst at Seoul’s Institute for National Security Strategy. Two key tiers are the State Security Bureau, a domestic spy agency, and the National Police. Both operate with little oversight or restraint from courts, media or human rights groups.

Security professionals are expected “to hear a pin dropping,” Mr. Kim said.

The third tier is the most intrusive: The Immin Ban — “People’s Class Unit,” or “Neighborhood Unit” — groups 10 to 20 nearby households together, tasking them to spy upon one another for anti-regime activity. All units are required to report to higher authorities. All are motivated by fear.

“It is not like they are influenced by rules. They are more influenced by punishment if they don’t report properly,” Mr. Kim said. “If a stranger appears, it’s a citizen’s responsibility to report it.”

Mr. Kim calls it “a perfect totalitarian regime.” It has proven incredibly effective over time: The only three serious challenges to 76 years of rule by the Kim family originated from within the military, not the general population.

So while Pyongyang may want Beijing-style digital surveillance, it may not need it.

“China is a beacon of freedom compared to North Korea,” Mr. Williams said.

• Andrew Salmon can be reached at asalmon@washingtontimes.com.